## TS 10th Class Biology Important Questions 10th Lesson Natural Resources

These TS 10th Class Biology Chapter Wise Important Questions 10th Lesson Natural Resources will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 10th Lesson Natural Resources

1 Mark Questions:

Question 1.
Suggest any two activities to check soil erosion in your school.
Answer:

• Observe the school ground after rain.
• Conduct a field project on soil erosion.

Question 2.
To create awareness on “Water conservation” in your locality, what slogan you will suggest?
Answer:

• “Don’t Waste Water”
• “Save every drop”
• “Water is life”

Question 3.
The symbol is there on the Item you bought. What it instructs?
(OR)
What does the given logo indicate ? What does It mean?
Answer:
It is the Recycle logo. It indicate that the item we bought is prepared from recycled materials or the item can be recycled after use.

Question 4.
What happens If the forest area decreases rapidly?
Answer:
If the forest area decreases

• It destroys wild life habitat.
• It increases soil erosion.
• It releases green house gases into the atmosphere contributing to global warming.
• It also harms people who relay on forest for their survival, hunting and gathering, harvesting forest products or using timber and firewood.

Question 5.
Write two activities which you are performing to save the electricity.
Answer:

• We can reduce the consumption of electricity by putting off the fans and lights when there is no need.
• We can use LED (Lighting Emitting Device) bulbs to save electricity.
• To shut down laptops and computers when they are not in use.

Question 6.
Prepare two slogans on protecting non-renewable resources.
Answer:

• Use Biofuel – Reduce Fossil Fuel.
• Use alternative resources – Save the environment.

Question 7.
Write two examples for non-renewable resources.
Answer:
The examples for non-renewable resources are coal, petroleum and natural gas.

Question 8.
Write any two measures you take in your home to reduce consumption of electricity.
Answer:

• We can use LED (Light Emitting Device) bulbs to save electricity.
• We can reduce the consumption of electricity by putting off the fans and lights when there is no need.

Question 9.
What is sustainable development? Why it is needful for us?
Answer:
When we use the environmeht in ways that ensure we have resources for the future, it is called sustainable development. It is needed because development and conservation can coexist in harmony.

Question 10.
Expand ICRISAT
Answer:
ICRISAT stands for International Crop Research Institute for Semi-Arid Tropics.

Question 11.
When can we say that the water resource Is scarce in an area?
Answer:
According to United Nations Development Programme, Water resource is an area, where annual water supply drops below 1700 m3 per person, is becoming scarce”.

Question 12.
What is the prediction of the food and Agriculture Organisation of the United Nations regarding water scarcity?
Answer:
The food and Agriculture Organisation of the United Nations has predicted that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity.

Question 13.
What is conservation?
Answer:
Conservation is the practice of caring for the resources, so all living things can benefit from them now and in the future.

Question 14.
Why are fossil fuels non-renewable?
Answer:
Fossil fuels are non-renewable. This is because it takes a long time for their formation while there consumption occurs very quickly.

Question 15.
What serves as a lung for the world?
Answer:
Forests serve as a lung for the world.

Question 16.
What is contour strip cropping? What is its use?
Answer:

• Contour strip cropping is a method of soil conservation.
• Several crops such as corn, wheat and clover are planted in alternating strips across a slope or across the path of the prevailing wind.
• Different crops with different roots systems and leaves, help to prevent soil erosion.

Question 17.
What is selective harvesting?
Answer:
The practice of removing individual plants or small groups of plant leaves, other plants standing to anchor the soil is called selective harvesting.

Question 18.
How many species are extinction every year ?
Answer:
Based on various estimates of the number of species on Earth, we could be losing anywhere from 200 to 100,000 species each year.

Question 19.
From where fossil fuels were produced?
Answer:
Fossil fuels were produced from the remains of ancient plants and animals.

Question 20.
Expand IUCN.
Answer:
IUCN stands for the International Union for the Conservation of Nature.

Question 21.
What is percolation tank?
Answer:
Percolation tanks are normally earthen dams with masonry structures where water may over flow.

Question 22.
What is micro-irrigation?
Answer:
Micro-irrigation is an irrigation method that saves water and fertilizers b allowing water to drip slowly to the roots of plants either on the soil surface or directly onto the root zone through network of valves, pipes, tubing. etc. Drip irrigation, sprinklers, etc., are collectively called as micro-irrigation.

Question 23.
Give an example of bio fuels.
Answer:
Seeds from the Jatropa curcas plant are used for the production of bio-fuel.

Question 24.
What are biodiversity hot spots ? What is the measure of the biodiversity?
Answer:
Forests are biodiversity hot spots. One measure of the biodiversity of an area is the number of species found here.

Question 28.
What is the effect of continuous depletion of ground water along coastal regions?
Answer:
The effect of continuous depletion of ground water along coastal regions will lead to movement of saline sea water into fresh water wells then spoiling their quality.

Question 29.
Write two points to be kept in mind while storing water in tanks.
Answer:

• Storage tank should not be located close to the source of contamination.
• It should be accessible for cleaning.

2 Mark Questions:

Question 1.
Why do we use fossil fuels judiciously?
Answer:

• Fossil fuels were produced from the remains of ancient plants and animals.
• They include coal, petroleum (oil) and natural gas.
• We need to use fossil fuels judiciously because they are non-renewable resources.
• We need to conserve fossil fuels so we don’t run out of them.
• The pollution caused by them when burnt, to limit our fossil fuel use.
• Future generations may not get these resources.
• Balance in the nature will be disturbed.
• Electricity production will be stopped.
• Vehicles running with fossil fuels become useless.

Question 2.
Write two suggestions to create awareness on groundwater conservation.
Answer:

• We need to adapt different methods to improve the quality and increase the quantity of groundwater.
• We should dig water harvesting pits for every house.
• We should clean the silt, mud fill in tanks and ponds.
• We should prohibit the establishment of borewells for extraction of groundwater for agricultural and industrial use.
• These measures will Improve quality and quantity of groundwater.

Question 3.
Suggest four measures to conserve fossil fuels.
Answer:

• Usage of alternatives to fossil fuel.
• Minimise the usage of fossil fuel.
• Walk, ride by bicycle and use public transportation whenever possible.
• Purchase energy efficient appliances.
• Turn off light and other electronics when you are not using them.

Question 4.
What is the importance of 4R’s In achieving the goal of “SwachhBharat”?
Answer:

• Reduce the production of garbage.
• Reuse the garbage for the production of manure and electricity.
• Recycle the garbage by separating it as dry and wet garbage.
• Recover the plants.

Question 5.
The Indiscriminate digging of Borewefls may result In what type of consequences in future?
Answer:

• Due to over drilling of borewells and pulling out water by electric motors, the ground water level is decreasing day by day.
• It is goes on without recharging, ground water becomes scarce.
• It shows impact on agriculture and the productivity will decrease.
• Fluorine levels in ground water will increase.
• Sometimes, saline water may intrude into the interior places of land and water becomes unfit for consumption.
• Farmers have to drill the bore wells to more depths which increase the losses for them.

Question 6.
Ramaiah made broad bed furrow around his field under employment guarantee scheme. Guess the reasons for it? If all the farmers of your village work together, will their water scarcity meet?
Answer:
The reason for Ramaiah making broad bed furrow around his field was, it is useful to conserve soil and water, fertilizer application weeding operations. It also conserve rain water. The farmers are over coming the water scarcity by sharing water available in the village. They formed groups of farmer including large and small ones who would use the same water resource. Farmers were also motivated to use irrigation techniques like drip Irrigation.

Question 7.
Write a short note on the distribution of water on earth.
Answer:

• Out of all the water on earth, salt water in oceans, seas and saline ground water make up about 97% of it.
• Only 2.5- 2.75% is fresh water.
• 1.75 – 2% of this is frozen in glaciers, ice and snow.
• 0.7 – 0.8% of water is present as fresh ground water and soil moisture.
• Less than 0.01% of water is present as surface water in lakes, swamps and rivers.
• Though this fresh water is a meagre portion of the whole, if used judiciously, shall last for a long time.

Question 8.
What are the disadvantages of deforestation ?
Answer:

• Deforestation destroys wildlife habitats.
• Deforestation increases soil erosion.
• It also releases greenhouse gases into the atmosphere, contributing to global warming.
• Deforestation accounts for 15 percent of the world’s green house gas emissions.
• Deforestation also harms the people who relay on forests for their survival, hunting and gathering, harvesting forest products or using the timber for firewood.

Question 9.
What is the importance of soil as a natural resource?
Answer:

• Soil is vital to food production.
• We need high-quality soil to grow the crops that we need.
• Soil is also important to plants that grow in the wild.
• Many other types of conservation efforts, such as plant conservation and animal conservation depend on soil conservation.

Question 10.
What is “Biodiversity”? What is its Importance?
Answer:

• Biodiversity is the variety of living things that populate the earth.
• The products and benefits we get from nature relay on biodiversity.
• We need a rich mixture of living things to provide foods and building materials, as well as to maintain a clean and healthy landscape.
• We need to protect biodiversity to ensure we have plentyful and varied food sources.
• Biodiversity is important for more than just food. For instance, we use between 50,000 to 70,000 plant species for medicines world wide.

Question 11.
How can we conserve fossil fuels?
Answer:

• Everyone can help conserve fossil fuels by using them carefully.
• Turn off lights and other electronics when you are not using them.
• Purchase energy – efficient appliances.
• Walk, ride a bike. Carpol and use public transportation whenever possible.
• It is better to prefer public transport system like bus or train instead of travel in personnel vehicles.
• Scientists are exploring alternatives to fossil fuels.
• They are trying to produce renewable biofuels to power cars and trucks.
• They have successfully produced electricity using the sun, wind, water, etc. So such source of energy should be encouraged.

Question 12.
What is the state of Minera is as a resource ? Mention two methods that help to conserve mineral resources.
Answer:

• Earth’s supply of raw mineral resources is in danger.
• Many mineral deposits that have been located and mapped have been depleted.
• As the ores for minerals like aluminium and iron became harder to find and extract, their prices go up.
• This makes tools and machinery more expensive to purchase and operate.
• Many mining methods, such as mountain top removal mining (MTR); devastate the environment.
• They destroy soil, plants and animal habitats.
• Many mining methods also pollute water and air as toxic chemicals leak into the surrounding ecosystem.
• Less wasteful mining methods and the recycling of materials will help conserve mineral resources.

Question 13.
Write about the four ‘Rs that can save environment.
Answer:
The four ‘R’ s that can save environment are:

1. Reduce
2. Reuse
3. Recycle and
4. Recover

1. Reduce: That is useless if you can afford to save water, repairing leaky taps and avoiding a shower or switching off unnecessary lights and fans.

2. Reuse: Things that you often tend to throw away, like paper that would save plants and wrapping papers that would minimise pollution.

3 Recycle: It is the process of converting waste materials into new materials and objects.
Ex: Some metals, glass, paper, etc. Recycling may not always be a very good option hut useful to conserve certain minerals. In Japan for example, car manufacturers recycle many raw materials used in making automobiles. In United states, nearly one-third of the iron produced comes from recycled automobiles.

4 Recover: When we cut trees to construct industries or roads for transportation, it is important to grow trees in another areas.

Question 14.
Why is recycling of plastic not a very good option?
Answer:

• Recycling of plastic may not always be a very good option as recycling plastic is a tricky process and can cause havoc.
• The chief problem lies in plastic’s complexity.
• There are as many types of plastic as their are uses.
• Since each type can only be recycled with its own kind, plastics need to be carefully sorted before they can be processed.

Question 15.
Draw the recycling logo.
Answer:

Question 16.
Draw the logo of sustainable development.
Answer:

Question 17.
Draw a pie diagram to show, the water sources and area under irrigation in our state.
Answer:

Question 18.
Why is scarcity of water there in our country in spite of nature’s monsoon bounty (large quantities)?
Answer:
It has taken place (due to the following reasons.

• Failure to sustain water availability under ground which has resulted largely from the loss of vegetation cover.
• Diversion for high water demanding crops.
• Pollution from industrial effluents and urban wastes.

Question 19.
Why is dependence of man on nature greater than that of any other organism?
Answer:
Man’s dependence on the environment is greater than that of other organisms because man

• Develops curiosity for more comforts and security.
• Consumes large amount of material and energy.
• Develops a new kind of socio-ecorìomic environment which consists of things developed by man through tools and techniques.

Question 20.
In addition to low rainfall, what are the other reasons for non availability of water in some regions of our country?
Answer:

• Flowing of rain water and lack of management to harvest it.
• Ground water is pumped out for high water departing crops.
• Water becomes unsafe and unusable due to mixing of urban wastes and effluents from the industries.

Question 21.
Write the advantages of giving control of water management to the residents of the area.
Answer:

• Water harvesting techniques are highly locality specific and the benefits are localised.
• Thus giving people control over their local water resources ensures that mismanagement and over exploitation of these resources is reduced.

Question 22.
What are the benefits of water harvesting?
Answer:

• Provides self sufficiency to water supply.
• Conserves valuable ground water.
• Reduces cost for pumping ground water.
• Reduces local flooding and drainage problems.

Question 23.
Why are environmentalists insisting upon substantial natural resource management ? Give any four reasons.
Answer:

• Non-renewable resources are limited. We should use them judiciously.
• We should encourage the use of renewable resources.
• We should preserve the environment for future generations.
• The benefits of the controlled exploitation should go to local people.

Question 24.
Observe the given diagram on percentage consumption of some resources in India. Add your comments on it.
Answer:
The above diagram shows the percentage consumption of various resources in India.

• The diagram shows that we are greatly dependent on fossil fuels for our energy resources.
• The percentage consumption under fossil fuels amounts to 73% coal being the highest consumed resource (42%) followed by oil (24%) and natural gas (7%).
• Very little percentage of resources were used under others (2%) and nuclear resource (1%).
• The most significant feature is that we are losing around 24% of resources as waste. This should he minimised to conserve usage of resources.

4 Mark Questions:

Question 1.
Forests are renewable resource. Write four sentences supporting this.
OR
“Forest is a renewable resource.” Do you agree? Justify.
Answer:

• Forests are rich habitat for plants and animals. Forests serve as a lung for the world and a bed of nutrients for new life to prosper.
• Pure air from forests protects the earth from green house effect by removing carbon dioxide and converting it into oxygen.
• Many fruits, medicines, dyes, sandle wood and bamboo is obtained from forest by local people.
• Forests provide employment to large number of people and also help in generating revenue.

Question 2.

Observe the above table and answer the following questions.

1. Which crop is most suitable to cultivate for small farmer in both the villages?
Answer: Cotton, paddy

2. If you are a large farmer, which crop do you select to cultivate?
Answer: Cotton, paddy, mirchi.

3. What similarities you have identified In village A and village B?
Answer: Small and large farmers cultivated same type of crop in both villages. Large farmer gets more income per acre on crops than small farmer in both the villages.

4. Which is the lowest income crop?
Answer: Mirchi.

5. Is there any relationship between production of crops and income? How?
Answer: Commercial crops are good for income. Income may or may not related to production of crop. It depends upon demand of the market.

Question 3.
Read the given information and answer the following questions.

A survey was conducted in two villages, Vanaparthy and Voddiche ria of Warangal district in Telan gana State. The first with no scarcity and the second with scarce groundwater. Well census was curried Out in the villages in order to get a complete picture of well irrigation and its status as well as the availability of water. There are no alternative sources of supply as against wells in Vaddicherla, where there is an existing tank that has been converted into a percolation tank, so the water situation is much better in Vano party.

i. Why did they conduct survey?
ii. What are irrigation resources in Telangana State?
iii. In which village, do you suggest drip irrigation?
iv. Why is the water situation much better in Vanaparthy village compared to Vaddlcherla?
Answer:
i.  A compartive study on available water resources irrigation method in the Vaddicharla and Wanaparthi of Warangal district of Telangana state.
ii. Lakes, wells, canals and ground water, etc.
iii. Vaddicherla.
iv. Existing tank has been converted into a percolation tank.

Question 4.
Observe the Pie diagram and answer the following questions.

i. Identify the fossil fuels from the above diagram.
Answer:
Coal, natural gas, oils are fossil fuels.

ii. Why wastes should be considered as primary energy source in future?
Answer:
The fossil fuels may be exhausted in future. So we may be considered that wastes are primary alternative energy resources.

iii. Why can’t we depend on fossil fuels forever?
Answer:
We can’t depend on fossil fuels forever because fossil fuels are non-renewable resources.

iv. What are the alternatives for fossil fuels?
Answer:
Solar energy, wind energy, tide energy, nuclear energy, energy from waste materials.

Question 5.
Explain the Importance and implementation of community based Interventions and farmer based Interventions for water management.
Answer:
Community based Interventions:

• For water harvesting, there is an urgent need to construct earthen and masonry dams. They help us to store rain water during rainy seasons. They are help in increasing the ground water table.
• Construction of percolation pits and field bunding are very helpful in the harvesting every rain drop.
• Open dry wells near nalla canal were recharged by building dykes or barriers in the nalla and maintaining the run-off rain water. The ground water is recharger these community-based Interventions.

Farmer based interventions:

• Broad Bed Furrow (BBF) land form and contour planting methods are very useful to conserve soil, water and fertilizer application and weeding operations.
• Planting Gliricidia, a leguminous plant adapted to grow in dry areas on field bunds to strengthen them and make the soil nitrogen rich.
• Farmers were encouraged to use water resource jointly and irrigate land using micro irrigation methods like sprinklers and drip irrigation.

Question 6.
Explain the farmer based and community-based interventions to conserve soil and water resources.
Answer:

Question 7.
“The humans who were developed by us the natural resources, today has econ the reason for destroying them”. Explain analytically.
Answer:
“The humans who were developed by using the natural resources, today has become the reason for destroying them” This statement is absolutely true.

1. Primitive man lived in forests and hills. H used the natural resources for his livelyhood. He worshipped nature and used them wisely for his development.

2. After his development, he becomes greedy and using the natural resources and is criminately and held responsible for their destruction.

3. To meet the needs of growing population, industrialization, urbanization, and huge constructive activities, man utlilsed natural resources indiscriminately. At the same time, he did not planned for their revival.

4. But now he realised the importance of natural resources and taken up steps for their conservation. The concept of “Sustainable development” is being implemented in natural resource management.

5. He focussed on development of alternatives for fossil fuels, conservation of water and soil at community level and farmer based interventions.

6. Now he is so keen on conserving forests, wild life and biodiversity.

7. He is so cautious in minimising the utilization of natural resources by following 4’R principle in the day today life
[R — Reduce, R — Reuse, R — Recycle, R — Recover]

8. Now, he is adopting micro-irrigation methods like sprinklers and drip irrigation to minimise the water usage in low water available areas.

9. He is very Interested in following eco-friendly techniques, natural farming methods, using biofertilizers,vermicompost and natural pest control methods in place of toxic chemical pesticides.

I. Conceptual Understanding

Question 1.
Write a short notes on the role of Governments and other organisations in conserving resources.
OR
Write a short note on IUCN.
Answer:

• Governments enact laws defining how land should be used and which areas should be set aside as parks and wildlife preserves.
• Governments also enforce laws designed to protect the environment from pollution, such as requiring factories to install pollution-control devices.
• Finally, governments often provide incentives for conserving resources.
• Many international organizations are also dedicated to conservation.
• Members support causes such as saving rain forests, protecting threatened animals, and cleaning up the air.
• The International Union for the Conservation of Nature (IUCN) is an alliance of governments and private groups founded in 1948.
• The IUCN works to protect wildlife and habitats.
• In 1980, the group proposed a world conservation strategy.
• Many governments have used the IUCN model to develop their own conservation plans.
• In addition, the IUCN monitors the status of endangered wildlife, threatened national parks and preserves and other environments around the world.

Question 2.
What programmes are you going to conduct to create awareness among farmer in your locality on waste land development?
Answer:
I will conduct following awareness programmes for farmers n our locality on waste land development.

• Conducts awareness programmes on soil importance how soil important for life.
• Growth of population is very rapid and cultivated land not increasing any more.
• Already tertile land being using for construction of house, factories and institutions land for cultivation becoming less day by day.
• Hence construction of new cities, airports, industries, institutions, it is better to use waste land.
• To increase the cultivated lard I will motivate the local farmers to bring waste land into cultivated land.

Question 3.
What changes would you suggest hi your home in order to be environment friendly?
OR
Write about the 4 ‘R’s needed in the protection and conservation of the environment.
Answer:
By pursuing tile maximum of tour R’s i.e., Reice, Reuse, Recycle and Recover, we can save the environment in an effective way.

1. Reduce: It want to use less, I would save electricity by switching off unnecessary heights and farts. prefer walking or cycling than using a vehicle, turn off the engine of car at red light, repair leaky taps and would not waste food.

2 Recycle: It means to collect used things like plastic, paper, glass and metal items and recycle these materials to make required things instead of synthesizing or extracting fresh plastic, paper, glass or metal.

3 Reuse: It refers to use things again and again. Fur example, instead of throwing away used envelopes, they can t)e used by pasting new labels.

4. Recover: We should implement ‘recover’ to prevent environmental threat. For example, when we cut trees to construct industries or roads for transportation, it is important to grow trees in another area.

II. Asking Questions And Making Hypothesis

Question 1.
The wells and tanks in your village become dry. Ground water levels decreased.
OR
Assume the causes for this. Will there be no water scarcity if all the farmers of your village work collectively?
Answer:
Causes for decreasing ground water levels:
1. Varying monsoon behaviour in recent years, there is pressure on ground water utilization.

2. Indiscriminate tapping of ground water in our village by too much drilling construction of deep tube wells and bore wells have resulted in over exploit on and depletion of ground water resources.

3.  There will be no water scarcity if all the farmers of our village work collectively. Farmers in our village were encouraged to use water resource jointly and irrigate land using micro irrigation techniques. By using micro irrigation techniques farmers in our village obtained more crop yield. Farmers in our village follow the micro irrigation method i.e. drip irrigation and can reduce water consumption by 70% in our village.

III. Communication Through Drawing, Model Marking

Question 1.
Draw a pie diagram showing percentage consumption of some resources in india.
Answer:

IV. Application to Daily Life, Concern to Bio-Diversity

Question 1.
Think that there is much scarcity of water for drinking and cultivation in your village. What advice do you give to prevent this?
OR
How do you overcome the problem of water scarcity in your village?
Answer:

• Motivate the people to conserve water.
• I will educate the people to avoid wastage of water whenever possible.
• Construction of recharge pits in the house, school and in the open areas to increase the underground water level.
• Planting trees wherever possible in the village, particularly in the vacant lands.
• Educate the farmers about the micro irrigation system like drip irrigation, sprinklers, etc.
• Encourage the farmers to form groups to share available air among themselves.
• Construction of percolation tanks in the low-lying areas of the village.

Question 2.
For which works fossil fuels are used in your house? What measures do you take to conserve them?
Answer:
Fossil fuels are sources of energy for cooking, heating and burning in our house holds. Petrol and diesel are being used in our house for transport and running generators and water pumps.

Measures to be taken to conserve fossil fuels in my house:

• I will put the food material to be cooked on the stove only after arranging all the things which are necessary for cooking.
• By using pressure cookers 20% gas on rice and 41.5% on meat would be saved when compared to other cooking means.
• We must reduce the flame as soon as the boiling process starts in a pressure cooker. This process saves nearly 35% of fuel.
• I will soak the food material before cooking. It saves 22% of fuel.
• I will cook food in broad and low depth vessel.
• I will keep Lid on the cooking vessel. If not, it takes more time to cook.
• For short distances to travel I will go by walk to save fuel for longer distance. I use public transport.
• Encourage people to use solar water heater and solar cooker.

Question 3.
How did centre for Wòrld Solidarity help the farmers in wanaparthy and Vaddicherla in recharging cells?
Answer:

•  A project of the centre for world solidarity that addresses sustainability of ground water intervened to help in recharging wells that were drying up in the villages – of Wanaparthy and Vaddicherla.
• They encouraged more water sharing among farmers.
• They formed groups of farmers including large and small ones who would use the same water resource.
• Farmers were also motivated to use irrigation techniques like drip irrigation, sprinklers, etc.
• Construction of soak pits to tap rain water optimally was carried out as community efforts.
• Soak pits helped in recharging dried-up horewells.
• Dykes or harriers. nearly 30 cm thick of brick-cement or stone cement harrier, extending down to the compact bed rock, with mud or clay fillings were built in underground streams to tap ground water optimally.
• Thus center for world solidarity helped the farmers in Wanaparthy and Vaddicherla in recharging ground water.

Question 4.
To make people as a part in development. and environment protection sustainable development write some slogans.
Answer:
Some of slogans are follow

• Development essential. but at cost our own destruction.
• Development and environmental protection are like our two eyes.
• For today’s happiness development don’t spoil tomorrow (environment).
• Development with the destruction of our environment will not stand for long time.
• If you protect the environment, it will protect you for generations. (You can add some more Slogans )

Question 5.
What steps you would like to follow on your part to conserve biodiversity?
Answer:

• Biodiversity is the variety of living things that populate the earth.
• To conserve biodiversity we should avoid hurting.
• Sustainable forest conservation methods should be followed.
• I will actively participate Vana mahosthavam programmes.
• I will educate and encourage people and make them participate in conservation programmes
• Create awareness programmes and around school.
• Writing slogans and also make some posters about conservation of biodiversity.
• Judicious use of electricity wherever possible.
• Finding out of various alternative sources of energy.
• Plant the saplings in the habitat.
• Encouraging of social forestry.

## TS 10th Class Biology Important Questions 9th Lesson Our Environment

These TS 10th Class Biology Chapter Wise Important Questions 9th Lesson Our Environment will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 9th Lesson Our Environment

1. Mark Questions:

Question 1.
What happens if decomposers are removed from the food web?
Answer:

• If decomposers are removed from the food web, then the biological cycles are not completed.
• If the decomposers are not present in an ecosystem, the remains of the other organisms accumulate.

Question 2.
Observe the following given below. Draw the pyramid of numbers.
Grass – Goat- Man
Answer:

Question 3.
We can’t expect the world without sparrows. So how should be our concern towards their conservation?
Answer:

• Sparrows are useful to control harmful insects like locust which damage food grains.
• Chemical pesticides are the cause for destruction of sparrows and useful insects.
• By using biological methods we can conserve the sparrow population.

Question 4.
Human being is modifying agriculture lands and lakes into residential areas. What is its effect on Bio-diversity?
Answer:

• Shelter may not be provided for migratory birds.
• Food chain gets disturbed.
• Decrease in the ground water level.

Question 5.
“We can’t imagine the world without insects and birds.” Suggest two methods to conserve them.
Answer:
Methods to conserve insects and birds:

• Avoid indiscriminate usage of pesticides
• Protect the natural habitats of insects and birds.
• Development of bird sanctuaries
• Everyone should follow environmental ethics.

Question 6.
The figure given below represents a food pyramid. Study it and answer the following questions.

i.  Which trophic level has maximum energy?
Answer: T1 (or) Primary producers (green plants)

ii. Give one example for T4 trophic level.
Answer: Lion, tiger, hawk, etc.

Question 7.
How do you protect the plants, which were planted in “Haritha Haaram” programme in your school?
Answer:
We protect the plants:

• Watering of plants at regular intervals.
• Fencing or gaurding of plants.
• Adoption of plants.
• Providing organic mannure.

Question 8.
What is biosphere?
Answer:
The world of living things is called “biosphere”.
(or)
The life supporting zone on the earth is termed as “biosphere”.

Question 9.
What determines the terrestrial ecosystems?
Answer:
The terrestrial ecosystems are being determined largely by the variations in climatic conditions between the poles and equator.

Question 10.
What does a food chain show?
Answer:
A food chain shows who eats what in a particular habitat.

Question 11.
What is the main source of energy for all the organisms in an ecosystem?
Answer:
Sunlight is the main source of energy for all the organisms in an ecosystem. Sunlight is trapped by the producers and passed to different levels of Consumers through food chain.

Question 12.
What is food web?
Answer:
Food web is the elaborate interconnected feeding relationships in an ecosystem. Many of the food chains in an ecosystem are crosslinked to form food web.

Question 13.
What does a food web indicate?
Answer:
food web suggests a far greater number of possible links for food in an ecosystem and reflects the fact that the whole community is a complex inter-connected unit.

Question 14.
What is ‘niche’?
Answer:
‘Niche’ is the term used to describe the role on organism or population plays within its community or ecosystem.

Question 15.
What does the word ‘niche’ denote?
Answer:
The term ‘niche’ denotes

• The animal’s position in the food web
• What it eats and
• Its mode of life.

Question 16.
What is an ecological pyramid?
Answer:
The graphic representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called “Ecological pyramid”.

Question 17.
What is pyramid of number?
Answer:
A graphic representation designed to show the number of organisms at each tropic level in a given ecosystem is called “pyramid of number”.

Question 18.
What does the pyramid of number show?
Answer:
Pyramid of number shows the population of organisms at each tropic level in a food chain.

Question 19.
What does each bar represent in a pyramid of number’
Answer:
In a pyramid of number, each bar represents the number of indMd’-ialS at each tropic level in a food chain.

Question 20.
When does the pyramid of number not look like a pyramid at all?
Answer:
The pyramid of number does not look like a pyramid at all
If the producer is a large plant such as a tree or if one of the organisms at any tropic level is very small, then the pyramid of number does not look like a pyramid.

Question 21.
What is biomass?
Answer:
Biomass is organic material of biological origin that has ultimately derived from the fixation of carbon dioxide and the trapping of solar energy during photosynthesis.

Question 22.
What is biofuel:
Answer:
Biomass used for energy production is called “Biofuel”.

Question 23.
What is pyramid of Biomass?
Answer:
A graphical representation designed to show the quantity of living matter at each tropic level in a given ecosystem is called “Pyramid of Biomass”

Question 24.
Why is pyramid of biomass inverted in case of aquatic ecosystem?
Answer:
In an aquatic ecosystem, the biomass of phytoplankton is quite negligible as compare to that of the crustaceans and small herbivorous fish that feed on these producers.
The biomass of large carnivorous fish living on small fishes is still greater. This makes the pyramid of biomass inverted.

Question 25.
How much percentage of the biomass is transferred from one tropic level to the next in a food chain?
Answer:
Nearly 10- 20% of the biomass is transferred from one tropic level to the next in a food chain.

Question 26.
When does the species at the top of the pyramid get more energy?
Answer:
The species at the top of the pyramid gets more energy, when the steps in a food chain are fewer.

Question 27.
What is ecological efficiency?
Answer:
The ratio between energy flows at different tropic levels among the food chain expressed as percentage is called “ecological efficiency”.

Question 28.
What is Bioaccumu talion?
Answer:
The process of entering of pollutants in a food chain is known as “Bioaccumulation”.

Question 29.
What is Biomagnificalion?
Answer:
The tendency of pollutants to concentrate as they move from one tropic level to the next is known as “Biomagnification”.

Question 30.
What are pesticides?
Answer:
The chemical materials used to control pests that attack crop plants or live as parasites on the body of farm animals are called pesticides.

Question 31.
What is a perfect pesticide?
Answer:
The perfect pesticide is one which destroys a particular pest and is completely harmless to every other form of life.
No such pesticide exists or likely to.

Question 32.
Who introduced the concept of Ecological pyramids for the first time?
Answer:
The concept of ecological pyramids was first introduced by a British Ecologist Charles Elton in 1927.

Question 33.
How can we draw a food chain?
Answer:
We can draw a food chain by connecting the pictures or names of organisms by putting arrows between them. These arrows should always point from food to the feeder.

Question 34.
How many types of ecological pyramids are there in practice ? Name them.
Answer:
There are three types of ecological pyramids. They are:

• Pyramid of number
• Pyramid of biomass and
• Pyramid of energy.

Question 35
Which process helps to convert solar energy into suitable form of energy for animals to consume?
Answer:
Photosynthesis helps to convert solar energy into suitable form of energy (food) for animals to Consume.

Question 36.
What limits the number of trophic levels in a food chain?
Answer:
There is a loss of energy as we go from one trophic level to the next, this limits the number of trophic levels in a food chain.

Question 37.
State one reason to justify the position of man at the apex of most food chains.
Answer:
The position of man is at the apex of most food chains as he is an Intelligent organism and can take any advantageous position by manipulation.

Question 38.
Which food chains are advantageous in terms of energy?
Answer:
Two step chains in which man is close to producer are advantageous.
For example: Producer – Man

Question 39.
Construct a food chain composing the following: Snake, Hawk, Rats, Plants.
Answer:
Plants – Rats – Snake – Hawk.

Question 40.
Which of the following will have the maximum concentration of harmful chemicals in its body?
Peacock, Frog, Grass, Snake, Grasshopper.
Answer:
Grass – Grasshopper – Frog – Snake – Peacock
Peacock will have maximum concentration,

Question 41.
Prepare two slogans to conserve water.
Answer:

• A drop of water is worth more than a sack of gold to a thirsty man.
• Don’t let the water run in the sink, our life is on the brink.

Question 42.
By taking two plants of your surroundings as examples, explain how they protect themselves against the animals which eat them.
Answer:

• Neem Tree: Neem leaves contain an alkaloid Nimbin to protect themselves from the animals which eat them.
• Cactus : They have thorns to protect themselves.
• Datura : Datura leaves gives bad odour.

2. Mark Questions:

Question 1.
Explain the flow chart given below.
Answer:

It is the pyramid of biomass.

• In this pyramid 10% of the food will reach to the next trophical level and so on at each level.
• It would take 1000 kg of phytoplankton to provide looking of zooplankton and to form 1kg of human tissue, 10 kg of frog is needed.
• The fewer the steps in the food chain, the more energy will be for the species at the top.

Question 2.
Observe the pyramid of number which is given below and answer the questions.

i.  As per the number of organisms in the tropic level, which group of organisms are more in number and which are less in number?
ii. What happens if Secondary consumers disappear?
Answer:

• If producers are more in number, then tertiary consumers are less in number.
• If secondary consumers disappear the primary consumers increase in number and the tertiary consumers found no food to live. It leads to death.

Question 3.
Explain in brief about the alternate methods to be followed to prevent the harmful effects of over usage of pesticides.
OR
Mention any four effective methods of controlling pests, which are less harmful on environment based on biological principles.
Answer:
Some of alternative pest control methods are

• Rotation of Crop: Growing different crops on a particular piece of land in successive years.
• Studying the life histories of the pests : When this is done it is sometimes possible to sow the crops at a time when least damage will be caused.
• Biological Control : Introducing Natural predator or parasite of the pest.
• Sterility: Rendering the males of a pest species sterile.
• Genetic Strains : The development of genetic strains (genetically modified plants) which are resistant to certain pest
• Environmental ethics: People need to know besides laws regarding environment there are some basic ethics what is right and what is wrong in view of environment.

Question 4.
Write any 4 slogans on the necessity of forests and on their conservation.
Answer:

• Save the trees, save the earth. We are the guardians of nature’s birth.
• Don’t destroy the greenery and don’t spoil the scenery.
• Don’t make trees rare, we should keep them with care.
• To live for future in rest, saving forest is the best.

Question 5.
How do the given below concepts differ?
a. Bioaccumulation
b. Biomagnification
Answer:
a. Bloaccumulation: The process of entry of pollutants into a food chain is known as bioaccumulation.
b. Blomagnification : It is the tendency of pollutants to concentrate as they move from one tropic level to the next is known as biomagnification.

Question 6.
The biomass of a producer in an ecosystem is calculated as 3500 kgs. Calculate the biomass of primary, secondary, tertiary consumers.
Answer:
In a food chain roughly 90% of the food is lost at each step. So if the biomass of a producer in an ecosystem is calculated as 3500 kgs. the biomass of primary consumer as will be 350 kgs. and of secondary consumer is 35 kgs and biomass of tertiary consumer is 3.5 kgs.

Question 7.
Write a short notes on ecological pyramids.
Answer:

• The graphic representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called “Ecological pyramid”.
• It was first introduced by a British Ecologist Charles Elton in 1927.
•  In the ecological pyramid, the producers (First tropic level) are represented at the base, and the successive tropic levels (primary, secondary and tertiary consumers) are represented one above the other with top carnivores at the tip.
• There are three types of pyramids.
i. Pyramid of number,
ii. Pyramid of biomass and
iii. Pyramid of energy.
• Pyramid of number shows the population of organisms at each tropic level in a food chain.
• Pyramid of biomass represents the available food as a source of energy at each tropic level in the food chain.
• Pyramid of energy represents the available energy at each tropic level in food chain.

Question 5.
How do pesticides cause Bioaccumulation and Biomagnification?
Answer:

• Pesticides are the toxic chemicals used to destroy pest and insects which damage our crops and stored foods.
• These pesticides vary in their length of life as toxic materials.
• Some of the pesticides are degradable that can be broken down into harmless substances in a comparatively short time and others are non-degradable.
• Non-degradable pesticides accumulate in the bodies of animal and pass right through food web.
• Thus the pesticides cause bioaccumulation.
• These accumulated pesticides concentrate as they move from one tropic level to the next, thus leads to biomagnification.

Question 6.
List out some human activities which altered the communities of plants and animals in their natural ecosystem.
Answer:

• Industrialization
• Damming rivers
• Draining marshes
• Re-claiming land from the sea
• Cutting down forests
• Using chemical fertilisers and pesticides
• Building towns, cities, canals and motor ways.

Question 7.
What kind of changes may come In an ecosystem due to development of a large town?
Answer:
The following changes are expected due to development of a large town.

• Some plants and animal species will die out.
• Some will adapt to the new conditions sufficiently to survive in reduced numbers.
• Some will benefit by the new conditions and will increase in numbers & Write a comparative note on pyramid of number and pyramid of biomass.

Question 8.
Write a comparative note on pyramid of number and pyramid of biomass.
Answer:

 Pyramid of number Pyramid of biomass 1. Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem. 1. Pyramid of biomass is a graphical representation designed to show the quantity of living matter at each tropic level in a given ecosystem. 2. It shows the population of organisms at each tropic level in a food chain. 2. It represents the available food as a source of energy at each tropic level in the food chain. 3. This pyramid sometimes does not look like a pyramid at all. It may be upright like a grassland ecosystem, partly upright like in forest ecosystem or inverted like in parasitic ecosystem. 3. This pyramid may be upright like in terrestrial ecosystem or inverted like in aquatic ecosystem.

4. Mark Questions:

Question 1.
Observe the following diagram and answer the following questions.

i. Name the primary producers in the given food web.
ii. Prepare any one food – chain from the diagram.
iii. What are the tertiary consumers?
iv. Write names of any two herivores.
Answer:
i. Plants, Grass, Trees Phytoplanktons etc.
ii. Grass → Rabbit → Fox →Tiger
iii. Tiger, Vulture, Crane, Owl, Peacock, etc.
(OR)
The animals which are at 4th trophic level a food chain are called as Tertiary Consumers.
iv. Rabbit, Deer, Goat, Cow.

I. Conceptual Understanding

Question 1.
What is number pyramid? What does it indicate?
Answer:

• The number of organisms in a food chain can be represented graphically in a pyramid of number.
• Each bar represents the number of individuals at each tropic level a food chain.
• At each link in a food chain, from the first order consumers to the large carnivores, there is normally an increase in size but decrease in number.
• For example in a wood. the aphids are very small and occur in astronomical numbers.
• The lady birds which feed on them are distinctly larger and not so numerous.
• The insectivorous birds which feed on the lady birds are larger still and are only present in a small number and there may only be a single pair of hawks of much larger size than the insectivorous birds on which they prey.

Question 2.
What reasons are responsible for decrease in number of top carnivores and biomass starting production in a food chain?
OR
Why does the number of organisms get decreased as we move from producers to consumer levels?
Answer:

• In a food chain as we move from producers to different levels of consumers the energy available will decrease gradually.
• Only ten percent of the energy present in one tropic level transfer to another tropic level.
• Biomass also decreases gradually as only 10 – 20% of the biomass is transferred from one tropic level to the next in a food chain.
• As there is less energy of less biomass available at top levels, number of organisms also less generally.
• So the number of organisms get decreased as we move from producers to different level of consumer.

Question 3.
What is Ecological pyramid ? Describe different types of Ecological pyramids.
Answer:
The graphic representation of the feeding level structure of an ecosystem by taking the shape of a pyramid is called “Ecological Pyramid. There are three types of ecological pyramids. They are
I. Pyramid of number
II. Pyramid of biomass and
III. Pyramid of energy

I. Pyramid of Number:

• Pyramid of number is a graphical representation designed to show the number of organisms at each tropic level in a given ecosystem.
• The shape of this pyramid varies from ecosystem to ecosystem.
• In aquatic and grassland ecosystems, numerous small autotrophs support lesser herbivores which support further small number of carnivores and hence the pyramid structure is upright.
• In forest ecosystem, less number of producers support greater number of herbivores who in turn support a fewer number of carnivores. Hence the pyramid structure is partly upright.
• In parasitic food chain, one primary producer supports numerous parasites which support still more hyperparasites. Hence the pyramid structure is Inverted.

II. Pyramid of Biomass:

1. Pyramid of biomass is a graphical representation designed to show the quantity of living matter (biomass) at each tropic level in a given ecosystem.

2. In terrestrial ecosystems, the biomass progressively decreases from producers to top carnivores. Hence the pyramid structure is upright.

3. In an aquatic ecosystem, the biomass of phytoplankton (producers) is quite negligible as compared to that of crustaceans and small herbivorous fish that feed on these producers. The biomass of large carnivorous fish living on small fishes is still greater. This makes the pyramid of biomass inverted.

III. Pyramid of Energy:

• Pyramid of energy is a graphical representation designed to show the quantity of energy present at each tropic level in a given ecosystem.
• The quantity of energy available for utilization in successive tropic levels is always less in any ecosystem. This is because there is loss of energy in each transfer. Hence the pyramid of energy is always upright.

Question 4.
What determines the terrestrial ecosystems on the earth?
Answer:

• The terrestrial ecosystems on the earth are being determined largely by the variations in climate conditions between the poles and equator.
• The main climatic influences which determine these ecosystems are rainfall, temperature and availability of light from the sun.
• For instance, forests are usually associated with high rainfall, but the type is influenced by temperature and light.
• The same applies to deserts which occur in regions where rainfall is extremely low.
• Thus, the climatic conditions along the horizontal climatic regions determined the terrestrial ecosystems on the earth.
• If we move from equatorial region to the polar region, we can come across tropical rain forests, savannah, deciduous fórest, coniferous forests and then tundras respectively.
• Similarly altitude of the place is also a determining factor.
• If we climb a mountain such as Kilimanjaro in equatorial Africa, we can go through a comparable system of ecosystems. starting with tropical rain forest at the base and ending with perpetual snow and ice at the summit.

Question 5.
Write a short note on food chain and food web.
Answer:

• Food chain is a pathway along which food ¡s transferred from one tropic level to another tropic level beginning with producers.
• It shows who eats what in a particular habitat.
• The arrows between each item in the chain always point from the food to the feeder.
• For example Grass → Rabbit → Snake→ Hawk
• The elaborate interconnected feeding relationships in an ecosystem is said to be food web.
• Many of the food chains in an ecosystem are crosslinked to form food web.
• For example,
• Food chain and food web help us to understand the food relations among living things.

Question 6.
Which pyramid is always upright? Why?
Answer:

• The pyramid of energy is always upright.
• This is because, only 10% of the energy present in a tropic level transfers to the other level.
• If there are 1000 calories of net production at producer level, only 100 calories of secondary production would be expected at the herbivore level, only 10 calories at level and I calorie at top carnivore level.
• The flow of energy from producers to consumers is unidirectional.
• So energy at producers level is always greater than the energy at primary consumer level and so on.
• Hence the pyramid of energy is always upright with a typical pyramid shape.
• But in case of pyramid of number, number of producers may be less than consumers in some ecosystems or number of primary consumers may be less than secondary consumers, etc. causing inverted or partly upright.
• In case of pyramid of biomass also the pyramid may inverted like in aquatic ecosystem, where the biomass of producers is less than that of consumers.

Question 7.
Why was anti-sparrow army established in 1958 in China?
Answer:

• Rural official overstated the amount of grain for fear of not meeting their Quota to China government.
• This over-reporting led to an imbalance between the demand and supply.
• The sparrows were accused of pecking away at the supplies in warehouses at an officially estimated rate of four Pounds of grain per sparrow per year.
• In the cities and the outskirts, almost half of the labour force was mobilized into the anti-sparrow army.

Question 8.
How did anti-sparrow army eradicate sparrows ? Is it right decision?
Answer:

• People started trapping, poisoning and killing sparrows in large numbers.
• Several free-fire zones were set up for shooting the sparrows.
• People would beat drums to scare the birds from cauding, so the sparrows were forced to keep flying until they dropped dead from fatigue.
• Sparrow nets were torn down, eggs were broken and nestlings were killed.
• Non-material rewards and recognition were offered to schools, work units and government agencies in accordance with the number of sparrows killed.
• No, it is not right decision Later years they come to know that decision of killing sparrows is wrong.

Question 9.
Were the sparrows really responsible for decrease in production ?How did they come to know it?
Answer:

• No, the sparrows really not responsible for decrease in production.
• Later some scientists who cut open the digestive systems of dead sparrows found that 3/4th of the contents were of insects harmful (or crops and only 1/4th contained grains.

Question 10.
Write some effective methods of controlling pests which have far less harmful effects and are based on sound biological principles. It is easy to say “Ban all pesticides” but the pests still have to be kept in check. How do you justify this statement?
Answer:
Some important effect biological pest controlling methods are:

• Rotation of crops: Growing different crops on particular piece of land in succession near reduces the pest on crops.
• Studying the life histories of the pest : When this is done it is sometimes possible to sow the crops at a time when least damage will be caused.
• Biological control : Introducing natural predators.
• Sterility: Rendering the males of a pest species sterile.
• Genetic strain : The development of genetic strains which are resistant to certain pest.
• Environment ethics: This is concerned with morality of human activities as they affect the environment. People need to know besides laws regarding environment. There are some basic ethics, what is right and what is wrong in view of environment.

IV. Information Skills And Projects

Question 1.
Collect information regarding pesticides commonly used in your area and prepare a chart showing pesticide and common name and on which crop and pest it is commonly used.
Answer:

V. Communication Through Drawing, Model Making:

Question 1.
Draw the diagram of number pyramid keeping foxes as third consumers. What are the consequences if their number increases?
Answer:

• If the number of foxes increases, then the complete Foxtion for food will be very severe and less amount of food will be available for them.
• As a result some of the foxes may not get enough food and die due to starvation.
• This reduces the population of foxes and very few foxes will be left in the forest.
• This increases the chances of survival of secondary consumers birds, hence their number increases.
• This increases the availability of food for foxes. Very soon a balance will be established between the number of secondary consumers and foxes.

Question 2.
Show food chain of different organisms, number of pyramid of your school.
Answer:
Food chain of different organisms in our school:
Plant aphids → spiders → birds.

• The pyramid of organisms in a food chain can be represented graphically in a pyramid of number.
• Each bar represents the number of individuals at each tropic level in a food chain.
• At each link in a food chain, from the first order consumers to the large carnivores, there is normally an increase in size, but decrease in number.

Question 3.
Draw a flow chart to describe the process of bioaccumulation and biomagnification of toxic pesticides In the body of eagles.
Answer:

Question 4.
Draw the ecological pyramids for the given food chain.
Banyan tree → Herbivorous birds → Carnivorous birds.
Answer:
1. Pyramid of number

2. Pyramid of biomass

3. Pyramid of energy

VI. Appreciation And Aesthetic Sense, Values

Question 1.
In a grassland ecosystem, some students are frying to kill the grasshoppers for fun. You don’t like this. How do you convince your friends not to do so?
Answer:
1. I will convince my friends to stop killing grasshoppers by explaining them about the food chain.

2. In grassland ecosystem grasshoppers are present at primary consumer level as shown hereunder.
Grass → Grasshopper → Frogs → Snake.

3.In grassland ecosystem frogs depend on grasshoppers for food. 1f students kill the grasshopper, the frogs die due to lack of food.

4. This shows a great impact on the snakes which depend on frogs for food. Every living organism on earth has right to live. We must respect other creatures on the earth.

5. So if grasshoppers are killed, it disturbs the food chain to a greater extent. Hence I advise my friends not to kill grasshoppers.

VII. Application To Daily Life, Concern To Biodiversity

Question 1.
Write what friendly ecosystem activities you will conduct in your school.
Answer:
1. Forming eco dubs: These clubs consists of student representatives from each class. They will take up the eco-friendly activities and encourage the people of that village to follow environment friendly activities.

2. Settling up garden at school : This ensures the school and its premises green through planting of flowering plants, vegetables and fruit trees. It is a symbol of biodiversity because various plants and animals inhabit the garden.

3. Electricity conservation programme : To save energy the school implements certain hours to be switched off habit. This switching off programme for one hour from 3.30 p.m. to 4.30 p.m. help conserve electricity in every class room.

4. Pollution prevention programme : A ‘no burning of trash’ policy should be implemented in the school. Waste materials are recycled and properly disposed to ensure a clean, waste-free environment.

5. Making compost by organic wastes: By digging a pit at one corner of the school and throwing the organic waste, particularly of mid-day meal waste into pit and covering with soil layers prepares compost which can be used as manure for plants. This creates a clean environment in the school.

6. Using cloth bags instead of polythene bags by pupil.

7. Collection of solid waste materials and proper management of its helps in reducing soil pollution.

8. Children should be encouraged to follow ‘3R’ system i.e. Reduce, Reuse and Recycle different substances.

Question 2.
If we introduce a man into a forest ecosystem, at which level of food chain we will place him? Explain your answer.
Answer:

• If we introduce a man into a forest ecosystem, he can fit for any level of Consumers of food chain.
• He may feed on plant parts such as fruits. Then we can place him at primary consumer level. Plant → Man
• He may feed on some of the herbivorous organisms such as rabbit, then we can place him at secondary consumers level. Plant → Rabbit → Man
• He may also feed on some of the carnivorous organisms such as insectivorous birds then we can place him at tertiary consumers level. Plant → Insect → Bird → Man
• This is possible to place him at any level of consumers, as he is an omnivore, who feed on both plant originated and animal originated foods.

Question 3.
‘All the energy in the ecosystem is ultimately derived from sunlight. “Justify.
Answer:

• All the organisms in an ecosystem derive energy from food.
• The food by its nature is the chemical energy and by in its stored form, it is the potential energy.
• In an ecosystem, all the consumers at any level depend upon producers for their food either directly or indirectly.
• The producers in any ecosystem are nothing but photosynthètic organisms such as plants, phytoplanktons and photosynthetic bacteria.
• Energy enters the producers in the ecosystem from the sun in the form of solar energy during photosynthesis.
• From the producers, the chemical energy passes to the consumers from the tropic level to the next through food.
• For example in a grassland ecosystem, grass traps the solar energy and stores in its body.
• When this grass is eaten and assimilated by insects this stored energy enters into the body of insects.
• From the insects it will pass to frog, from them to snake and so on to eagle.
• Thus, all the energy in the ecosystem is ultimately derived from sunlight.

Question 4.
Howaresparrows really helpful to farmers in China?
Answer:

• After anti-sparrow campaign, some scientists cut open the digestive systems of dead sparrows found 3/4 of contents were insects and 1/4 of contents contained grains.
• These sparrows are very useful in eradition of harmful insects in feuds and improve yielding.

## TS 10th Class Biology Important Questions 8th Lesson Heredity and Evolution

These TS 10th Class Biology Chapter Wise Important Questions 8th Lesson Heredity and Evolution will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 8th Lesson Heredity and Evolution

1 Mark Questions:

Question 1.
When cross is done between pure yellow and pure green pea seed-producing plants the following results were obtained. (Y = yellow ; y = green)
Answer:
Answer the questions given below based on the above table.

i. Yy – indicates which colour of the seed?
Answer: Yy – indicates the Yellow colour of the seed.

ii. What is the Phenotypic ratio of the above cross?
Answer: Phenotypic ratio of the above cross is 3: 1

Question 2.
Observe the given How-chart and answer the question.
Who decides the sex of the baby – mother or father? How?
Answer:

Father decides the sex of the baby.
Mother has XX chromosomes. Father has ‘XY’ chromosomes.
Y chromosome is determining factor. So father is responsible.

Question 3.
What examples will you give to prove that Lamarcklsm is not correct?
Answer:
Augustus Weismann, tested the theory proposed by Lamarck by experiments on rats.
He removed tails of parental rats. He observed for twenty two generations but still off springs are normal with tails.

Question 4.
Which chromosomes determine the sex in human beings?
Answer:
Allosomes or Sex chromosomes. They are XX (girls) and XY (boys).

Question 5.
Why do we call appendix as a vestigial organ?
Answer:

• Vestigial organ is the organ of our body which is smaller and simpler than those in related species they have lost their original function.
• Appendix is highly developed in ruminants which helps in the digestion of cellulose. But, in human beings the cellulose is eliminated as undigested food. Hence in human beings appendix has no role in cellulose digestion. So, we call it as a vestigial organ.

Question 6.
What are variations?
Answer:
Differences in characters within very closely related groups of organisms are referred to as “variations”.

Question 7.
What is F1 generation?
Answer:
F1 generation or first filial stands for offsprings of first generation parents.

Question 8.
What is F2 generation?
Answer:
F2 generation is the offsprings produced either by self hybridization or inbreeding from F1 individuals.

Question 9.
What is F3 generation?
Answer:
F3 generation represents the offsprings produced from the individuals of F2 generation.

Question 10.
What is phenotyperatio?
Answer:
The characters which can be seen is known as phenotype and their ratio is called “phenotype ratio”. The phenotype ratio in F2 generation of monohybrid cross is 3: 1.

Question 11.
What is genotype ratio?
Answer:
The genetic makeup of an individual with reference to a specific character under consideration is called genotype and their ratio is called “genotype ratio”. It indicates the internal factors. The genotype ratio in F2 generation of monohybrid cross is 1: 2: 1.

Question 12.
State the law of Independent assortment.
Answer:
In the inheritance of more than one pair of characters (traits), the factors for each pair of characters assort independently of the other pairs. This is known as law of independent assortment.

Question 13.
What is allele?
Answer:
The pair of genes which are responsible for character is called “allele”.

Question 14.
Whatare genes?
Answer:
Genes are the factors which are responsible for character or trait of an organism.
These are the units of heredity that is transferred from a parent to offspring. These are the segments of nucleic acid called ‘DNA’ which is present in the nucleus of every cell.

Question 15.
What are homozygous alleles?
Answer:
Homozygous alleles are the same alleles. Either both dominant are both recessive. Ex : TT, tt.

Question 16.
What is heterozygous allele?
Answer:
Heterozygous allele is that which has both dominant and recessive genes. Ex : Tt.

Question 17.
What is law of dominance?
Answer:
According to Mendel, among a pair of alleles for a character, only one expresses itself in the first generation as one of the allele is dominant over the other. This is known as law of dominance.

Question 18.
State the law of segregation.
Answer:
The law of segregation states that every individual possesses a pair of alleles for any particular trait and that each parent passes a randomly selected copy of only one of these to its offspring.

Question 19.
What are inherited traits
Answer:
The characters which pass from parents to children or from one generation to next generations are called “Inherited Traits” or “Inherited Characters”.

Question 20.
What is heredity?
Answer:
The process of acquiring characters or traits from parents is called “Heredity”.

Question 21.
What is Inheritance?
Answer:
The process in which traits are passed from one generation to another generation is called “Inheritance”.

Question 22.
What are autosomes?
Answer:
Chromosomes whose number and morphology do not differ between males and females of a species are called autosomes.

Question 23
What are allosomes?
Answer:
Sex determining chromosomes are called allosomes or sex chromosomes. in humans there is a pair of allosomes. There are two types of allosomes in human, one is X and second one is Y.

Question 24.
What are acquired characters?
Answer:
Characters that are developed during the lifetime of an organism are called “acquired characters”.

Question 25.
What is inheritance of acquired characters?
Answer:
Lamarck proposed that the acquired characters are passed to its offspring. i.e. to next generation. This Is known as “Inheritance of acquired characters”. For example elongation of neck and forelimbs in giraffe.

Question 26.
What is meant by survival of the fittest?
Answer:
Nature favours only useful variations. Each species tend to produce large number of offspring. They compete with each other for food, space, mating and other species. In this struggle for existence, only the fittest can survive. This is called survival of the fittest.

Question 27.
What is micro evolution?
Answer:
Small changes within the species is known as micro evolution.

Question 28.
What is macro evolution or speclation?
Answer:
The process of evolution through which new species are going to be formed is known as speciation or macro evolution.

Question 29.
What are homologous organs?
Answer:
Organs which have a common fundamental anatomical plan and similar embroyonic origin whatever varied functions they may perform are called homologous organs. Ex: Flippers of a whale, wing of a bat, forelimb of a horse, forelimb of human.

Question 30.
What are analogous organs?
Answer:
Analogous organs are those that perform similar functions but have entirely different embryonic origins.
Ex : Wing of a bird and wing of a bat.

Question 31.
What is embryology?
Answer:
Embryology is the study of the development of an organism from egg to adult stage.

Question 32.
What are fossils?
Answer:
Fossils are evidence of ancient life forms or ancient habitats which have been preserved by natural processes.

Question 33.
What is Palaeontology?
Answer:
The study of fossil is called “Palaeontology”.

Question 34.
What is the method used to determine the age of the fossil?
Answer:
Carbon dating is the method used to determine the age of the fossil.

Question 35.
What is human evolution?
Answer:
Human evolution is the evolutionary process leading up to the appearance of modern human beings.

Question 36.
How do variations occur?
Answer:
Variations dey lop during reproduction In organisms. Sexual reproduction and errors in DNA copying lead to variations in offspring in a population.

Question 37.
What is divergent evolution?
Answer:
The evolutionary process through which homologous organs develop is called divergent evolution.

Question 38.
What is convergent evolution?
Answer:
The evolutionary process through which analogous organs develop is called convergent evolution.

Question 39.
Where were the fossils of dinosaurs collected in our state from?
Answer:
The fossils of dinosaurs and ketosaurs were collected from Yamanapalli in Adilabad district in Telangana state.

Question 40.
What are vestigial organs?
Answer:
Organs which are not useful in animal are called vestigial organs.

Question 41.
Who was the first person to propose the theory of evolution?
Answer:
Jean Baptist Lamarck was the first person to propose the theory of evolution.

Question 42.
Who proposed the theory of Inheritance of acquired characters?
Answer:
Jean Baptist Lamarck proposed the theory of Inheritance of acquired characters.

Question 43.
Who proved that the bodily changes which may occur due to environment won’t be passed to its offsprings?
Answer:
Augustus Weismann proved that the bodily changes which may occur due to environment won’t be passed to its offspring.

Question 44.
Who proposed the theory of Natural selection?
Answer:
Charles Darwin proposed the theory of Natural selection.

Question 45.
What does the theory of Natural selection state?
Answer:
The theory of Natural selection states that nature only selects which organism should survive or perish in nature. The organisms with useful traits will survive. The organisms having harmful traits are perished or eliminated from its environment.

Question 46.
How many vestigial organs are there in human beings?
Answer:
There are nearly 180 vestigial organs in human beings.

Question 47.
Give some examples for vestigial organs in man.
Answer:
Pinna, hair on skin, mammary glands in man, appendix, etc. are the examples for vestigial organs.

Question 48.
Which organism is said to be a moving museum of vestigial organs?
Answer:
Human being is said to be a moving museum of vestigial organs.

Question 49.
How can one change adopted perform different functions?
Answer:
The study of evolution reveals one change occurred initially is used to perform other function. For example initially feathers were evolved for warmth, later they were adapted for flight.

Question 50.
Why are traits acquired during the lifetime of an individual not inherited?
Answer:
Any change in somatic cells cannot be passed to DNA of germ cells. Hence these traits are not inheritable.

Question 51.
What factors could lead to rise of a new species?
Answer:

• Genetic variation
• Natural selection
• Genetic drift

Question 52.
Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?
Answer:
No, though the function of wings in both the cases is same they are structurally different and their origin is also different. They are analogous organs.

Question 53.
If the sperm bearing ‘Y’ chromosome fertilizes the egg, the child born will not be entirely like his father, why is it so?
Answer:
It is because the other sex chromosome, i.e. X- chromosome also has its effect on the fertilized egg.

2 Mark Questions:

Question 1.
Is variation all about apparent differences ? Or is it about some subtle differences as well that we most often overlook?
Answer:

• Variations are not always apparent differences.
• Sometimes these may be subtle differences that we most often overlook.
• When these subtle differences accumulate together they may become apparent.

Question 2.
How do parent plants pass on their traits to the seeds?
Answer:

• Every character or trait is controlled by a pair of factors called genes.
• At the time of sexual reproduction one factor or each trait will pass to the gametes.
• By the fusion of male and female gametes zygote will form in which factors from both male and female parents get paired again.
• This zygote will develop into seed in the later stages.
• Thus parent plants pass on their traits to the seeds.

Question 3.
Will the seeds from tall plants always produce new tall plants?
Answer:

• No. Tall plants may or may not produce tall plants again.
• This is because tallness is a dominant character in most of the plants especially in peas.
• So tall plant may be homozygous tall (TT) or heterozygous tall (Tt).
• If the parental plant is homozygous tall (pure breed), then they always produce new tall plants.
• If the parental plant is heterozygous tall plant, then they produce the tall and dwarf plants in the ratio of 3: 1

Question 4.
Who decides the sex of the baby – mother or father?
Answer:

• Sex determination of the baby depends on the sex chromosome carried by the sperm, as the ovum always carries X chromosome only.
• If the sperm with X chromosome fuses with ovum, the baby will have XX condition. So he baby will be a girl.
• If the sperm with Y chromosome fuses with ovum, the baby will have XY condition. So the baby will be a boy.
• So the sperms that come from father decides the sex of the baby.
• In fact it is by mere chance and the chance for any sex formation is 50% as the male produces both sperms with X and sperms with Y are produced in same number.

Question 5.
How does the evolution of organisms take place?
Answer:

• Variations which are beneficial are selected by the nature and passed from parents to offspring through heredity.
• The same process happens with every new generation until the variation becomes common feature.
• As the environment changes, the organism within environment adapts and changes to the new living conditions.
• Over a long period of time, each species of organisms can accumulate so many changes that it becomes a new species.
• Thus evolution of organisms took place from common pre-existing ancestors.

Question 6.
Think why ancient human beings travelled from one place to other and how they travelled.
Answer:

• Ancient human beings travelled from one place to other in search of better living conditions such as availability of food, water and other facilities.
• They did not travel in a single line.
• They went forwards and backwards with groups, sometimes separating from each other.
• This travel is responsible for the formation of races.

Question 7.
Explain the theory of “inheritance of acquired characters” with an example.
Answer:

• Jean Baptist Lamarck proposed the theory of inheritance of acquired characters.
• According to this theory the new character that are developed during the life time of an organism are passed to next generation.
• For example initially giraffee was equal to deer. Due to shortage of food materials and to reach the lower branches of tree giraffee started stretching its neck.
• Because of continuous stretchness of neck after several generations giraffee developed long neck.
• Such character that are developed during the life time of an organism are called acquired characters. These acquired characters are passed to next generation.

Question 8.
Who decides the sex of the baby, mother or father Explain with a flow chart.
Answer:
Father decides the sex of the baby.
(Or)
Draw a flow – chart showing the sex determination in human beings.

Question 9.
Define the terms phenotype and genotype.
Answer:
Phenotype: The observable properties of an organism that are produced by the interaction of the genotype and the environment. These characters can be seen.
Genotype : The genotype is the genetic make-up an individual usually with reference to a specific characteristic consideration.

Question 10.
What questions you will ask a palaeontologist about fossils?
Answer:

• What are fossils?
• How do they preserve?
• What can be the actual remains?
• How do they form?
• What do we call the study of fossil?
• Can you tell some examples of fossils?
• Flow do the palaeontologists determine the age of fossils?
• What are dinosaurs and ketosaurs ? In which years they belong?
• Where did they collect the fossil of dinosaurs ? What is the length of this fossil?
• Where did they preserve the fossil of dinosaurs?

Question 11.
Observe the checker board and answer the following questions.
i. Write phenotypic ratio of monohybrid cross. :
ii. How many heterozygous plants are present in the checker board? “
Answer:

• Phenotypic ratio 3: 1
• Two heterozygous plants

Question 12.
How does the embryological evidences support that Evolution has taken place?
Answer:
Evidences:

• Remarkable similarities in the Embryos of different animals from fish to man.
• Tadpole of frog resembles the fish more than the frog.
• Life history of every individual exhibits the structural features of their ancestors.
• The resemblance is so close at an early stage, it is difficult to distinguish one embryo from other.

Question 13.
What happens if there is no evolution?
Answer:

• Evolution is a continuous and comprehensive process.
• If it does not take place, there is no formation of new species.
• Variations do not take place and hence desirable traits are not developed.
• All the Earth would be with the primitive species without any changes.

Question 14.
If you cross a plant with pure yellow seeds (YY) with a plant with pure green seeds (yy), what would be the colour of the seeds in F2 generation ? Show in a checker board.
Answer:

All pea plants are yellow in F1 generation on self pollination in F1 generation

In F2 generation, we can observe that 75% are yellow seed producing pea plants and 25% are green ones.
Hence the phenotypic ratio is 3: 1 the genotypic ratio is 1: 2: 1

4 Mark Questions:

Question 1.
Explain sex determination in humans with the help of flow chart.
Answer:

• Each human cell contains 23 pairs (46) of chromosomes.
• Out of 23 pairs, 22 pairs of chromosomes are called autosomes.
• Remaining one pair is called allosomes or sex chromosomes.
• There are two types of sex chromosomes – one is ‘X’ and the other is ‘Y’.
• These two chromosomes determine the sex of an individual.
• Females have two ‘X’ chromosomes in their cells (XX).
• Males have one ‘X’ and one ‘Y’ chromosomes in their cells (XY).
• All the gametes produced by women (ovum) will be with only X chromosomes.
• The gametes produced by man (sperm) will be of two types, one with X chromosomes and other with Y chromosomes.
• If the sperm carries X chromosome and fertilizes with the ovum, the resultant baby will have XX condition. So the baby will be a girl.
• If the sperm carries Y chromosome and fertilises with the ovum, the resultant baby will have XY condition. So the baby will be a boy.

Question 2.
What are Mendel’s laws of inheritance? What are the reasons to choose pea plant for his experiment?
Answer:
Mendel’s Laws of inheritance:
1. Law of Dominance : Among a pair of closely related ‘alleles’ or factors, only one expresses itself. In the first generation as one of the allele is dominant over the other. This is called as Mendel’s Law of dominance.

2. Law of Seggregation : The law of seggregation states that every individual possesses a pair of alleles for any particular trait that each parent posses a randomly selected copy only one of these to its off-spring.

3. Law of Independent assortment: In the inheritance of more than one pair of characters (traits), the factors for each pair of characters assort independently of the other pairs. This is known as ‘Law of Independent assortment’.

Mendel has chosen garden pea as material for his experiment because:

• It has well developed characters.
• It is a bisexual flower,
• Predominently self pollinating.
• Suitable for cross pollination.
• It is an annual plant.

Question 3.
What is Phenotype and Genotype? Explain them with the help of Mendel’s Monohy brid cross.
Answer:
Phenotype: Expression of visible character of an individual is called phenotype.
Genotype: Genetic constitution of an individual for any character is called Genotype or Probable nature of factors is known as genotype.

Cross Pollinating a pure breed of yellow coloured pea seeds (YY) and green coloured pea seeds (yy) give F1 generation. All pea seeds were yellow in F1 generation. So, yellow colour is phenotype. ‘Yy’ is genotype of all pea seeds in F1 generation.

F2 Generation: Self pollination of F1 pea plants Yy

Phenotype Ratio is 3:1 Genotype Ratio is 1:2:1.

Question 4.
Explain in brief any two evidences of Evolution.
Answer:
Some of the evidences of evolution are
I. Homologous and analogous organs
II. Evidences from embryology and
III. Evidences from fossils.

I. Homologous and analogous organs:

• Organs which have common fundamental anatomical plan and similar embryonic origin, whatever varied functions they may perform are regarded as homologous organs.
• For example forelimb of a whale, wing of bat, leg of leopord, claw of mole and hand of man.
• They indicate that all the vertebrates are evolved from common ancestor.
• Organs which are structurally different but functionally similar are known as “Analogous organs”.
• For example wings of bats and wings of birds.
• The designs of the two wings, their structure and components are different but they look similar because they have a common use for flying but their origin is not common.

II. Evidences from embryology:

• There are remarkable similarities in the embryos of different animals from fish to man.
• The resemblance is so close that at an early stage even an experienced embryologist would find difficulty to distinguish one embryo from the other.
• This strengthens the view of the existence of a common ancestor from which all these have evolved.

III. Evidences from fossils:

• Fossils are evidences of ancient life forms or ancient habitats which have been
preserved by natural processes.
• Palaeontologists determine the age of fossils by using carbon dating method.
• These fossils provide evidences of presence of extinct animals like dinosaurs and how the evolution occurred on the earth, etc.

Question 5.
Observe the given flow-chart and answer the following questions:

i. Name the chromosomes that determine the sex of an individual.
Answer:
Y Chromosome of father.

ii. Show given Information in the form of Checker Board.

iii. In this situation, which principle of Mendel Is applicable?
Answer:
Law of dominance

iv. “Mother determines the sex of the baby”. Is this statement correct or not? Why?
Answer:
The statement is not correct. Because the sperm of father that carries Y chromosome fertilize with ovum of mother that contains X chromosome the resultant will be XY – Male baby.

I. Conceptual Understanding

Question 1.
Keep in mind Mendel‘s experiments and write what you know about the following
a. Pure breed
b. Phenotype
c. Genotype
d. Alleles
Answer:
a. Pure breed : These are such kind of plants that expresses a selected character, over several generations. Such plants according to Mendel were pure breed for that character.

b. Phenotype: The characters which can be seen is known as phenotype. We cannot determine the internal factors by phenotype. It tells about only the dominating characters which express externally. The phenotype ratio in monohybrid cross is 3: 1.

c. Genotype : The genetic make up of an individual is known as genotype. Genotype itself is the indication of internal factors. It tells about both dominant and recessive characters present within. The genotype ratio in monohybrid cross is 1: 2: 1.

d. Alleles: Alleles are corresponding pairs of genes located at specific positions in chromosomes. Together they determine the genotype of their host organism. Every individual possesses a pair of alleles for any particular trait and that each parent passes a rondomly selected copy of only one of these to an offspring. The offspring then receive their own pair of alleles for that trait one each from both parents.

Question 2.
What is natural selection? How does it direct the evolution ? Explain with an example.
Answer:

• Natural selection states that nature only selects or decides which organism should survive or perish in nature.
• The organisms with useful traits will survive and the organisms having harmful traits are going to be perished or eliminated from its environment.
• Let us consider a group of red beetles which live in bushes on green leaves and grow by sexual reproduction.
• Let us assume crows eat these red beetles.
• Let us consider one colour variation arises during reproduction so that there is abeetle that is green in colour instead of red.
• Moreover, this green colour beetle passes its colour to its offspring, so that all its progeny are green.
• Crows cannot see the green coloured beetles on green leaves of the bushes and therefore crows cannot eat them.
• But crows can see the red beetles and eat them.
• As a result, there are more and more green beetles than red ones which decrease their number
• The variation of colour of beetle ‘green’ gave a survival advantage to ‘green beetles’ than red beetles.
• In other words, it was naturally selected by means of crows.
• The more crows there are, the more red beetles would be eaten and the more number of green beetles in the population would be. Thus the natural selection is directing evolution in the beetle population.

Question 3.
What is genetic drift ? Explain how it provides diversity in the population.
Answer:

• Changes in the frequency of genes in small populations, due to accidents is known as “Genetic drift”.
• Let us consider a colour variation occurred in red colour beetles which are living on green coloured leaves of bushes.
• It results in “blue” colour beetles instead of ‘red’ colour beetles and passed its colour to its progeny.
• Initially in the population, there are few blue beetles, but most are red.
• Imagine at this point, an elephant comes by and stamps on the bushes where the beetles live.
• This kills most of the beetles but by chance a few beetleš survived are mostly blue.
• Again the beetle population slowly increases, but in the beetle population most of them are in blue colour.
• Thus genetic drift provides diversity in the population.

Question 4.
Write the main points in the Darwin theory of evolution in a nutshell.
Answer:
Darwin’s theory of evolution in a nutshell:

• Any group of population of an organism contains variations and not all members of group are identical.
• Variations are passed from parent to offspring through heredity.
• The natural selection over abundance of offspring leads to a constant struggle for their survival in any population.
• Individual organisms with variations that help them to survive and reproduce tend to live longer and have more offsprings than organisms with less useful features.
• The offsprings of survivors inherit the useful variations, and the same process happens with every new generation until the variation becomes a common feature.
• As the environment changes, the organism within the environment adapts and changes to the new living conditions.
• Over a long period of time, each species of organism can accumulate so many changes that it becomes a new species, similar to, but distinctly different from the original species. All species on the earth arise in this way.
• Evolution is a slow and continuous process.

Question 5.
How are new species evolved?
Answer:

• Sexual reproduction and errors in DNA copying leads to variations in offspring in a population.
• Organisms contain variations that help to adapt to its environment going to be survived more efficiently.
• But in the same population, the organisms which contain the trait which may not help to adopt in its environment may be perished or eliminated slowly.
• These small changes within the population due to variations is called micro evolution.
• When organisms of the same species with variations are separated by some cause for long years, lot of variations may take place in these years.
• These accumulated variations make them unable to mate and produce new offsprings.
• Thus new species form and this is known as speciation or macro evolution.

Question 6.
What are fossils ? Write a short note on their formation.
Answer:

• Fossils are evidence of ancient life forms or ancient habitats which have been preserved by flatural processes.
• Fossil evidence is typically preserved within sediments deposited beneath water and land.

II. Asking Questions And Making Hypothesis

Question 1.
What is meant by law of dominance ? To know more about law of dominance, what kind of questions will you ask?
Answer:
i. Out of a pair of contrasting characters present together only one is able to express itself while the other remain suppressed is known as law of dominance
ii. I will ask following questions to know more about law of dominance:

• Who proposed law of dominance?
• Which plant Mendel took for his experiments?
• Why he (Mendel) took pea plant for his experiments?
• How many contrasting characters he choose in pea plant?
• How can you correlate law of dominance in daily life situation?
• Tall / dwarf – which one is dominant character?
(You can add some more questions related to concept )

Question 2.
What are the hypothesis assumptions and outcomes of Mendel’s experiments with pea plants?
Answer:
Regarding his experiments with pea plants, Mendel hypothesised that

• Characters were carried as traits and an organism always carried a pair of factors for a character.
• The distinguishing traits of the same charater were present in the population of an organism.
• The traits shown by the pea plants must be in the seeds that produced them.
• The seeds must have obtained by the traits from the parent plants.

His assumptions made to explain his observations are:
Assumption 1: Every pea plant has two ‘factors’ which are responsible for producing a particular property or trait.
Assumption 2: During reproduction one ‘factor’ from each parent is taken to form a new pair in the progeny.
Assumption 3: One of these will always dominate the other if mixed together.

Laws made from his experiments:

• Law of Dominance : Among a pair of alleles for a character, only one expresses itself in the first generation as one of the allele is dominant over the other.
• Law of Segregation : Every individual possesses a pair of alleles for any particular trait and that each parent passes a randomly selected copy of only one of these to its offspring.
• Law of Independent Assortment: In the inheritance of more than one pair of characters the factors for each pair of characters assorts independently of the other pairs.

III. Experimentation And Field Investigation

Question 1.
The cross between Hybrid tall (Tt) and dwarf (tt), what will be F1 generation progency. Write phenotypic and genotypic ratio.
Answer:

Phenotype ratio 1: 1
Genotype ratio 1: 1

Question 2.
What will be phenotypic and genotypic ratio if cross between pure Red (RR) and Hybrid Red (Rr)?
Answer:
Parents are RR and Rr.

Phenotypic ratio 2 : 0
Genotypic ratio 1: 1: 0

V. Communication Through Drawing, Model Making

Question 1.
Draw the diagram of monohybrid cross and explain it.
Answer:
A cross-pollination between a pure breed of yellow seed bearing plant and green seed bearing plant gave the following results:
First Filial / F1-generation : (Filial means progeny)
All pea seeds were Yellow. On self-pollination of these pea plants the following results were obtained :
All pea seeds were yellow.

Second Filial / F2-generation : The F2 generation had about 75% of yellow seeded pea plants and 25% of green seeded pea plants, i.e. they appear in 3: 1 ratio.

Adding to above results, Mendel made following observations:

• A set of peas (about 25%) obtained in F2 generation are yellow seeded plants (Hornozygous dominant).
• A Set of peas (about 50%) obtained in F2 generation are heterozygous yellow and give yellow and green seeds in 3:1 on self pollination.
• A set of peas (about 25%) obtained in F2 generation are green seeded. On self-pollination they keep producing green seeded plants (Homozygous recessive).

VI. Apprecition Andthetic Sense, Values

Question 1.
How will you appreciate Mendel’s work?
Answer:

• Mendel laid foundation to hybrid varies in plants.
• Because his works and law’s (Mendel’s laws) became guide to later generation scientist.
• So many plants with desirable characters created, which are helpful to mankind.
• His works help the scientist to find new varieties of species in animals.
• Ultimately more desirable plants and animals came into existence.

Question 2.
How would you appreciate Gregor Johann Mendel’s contribution to the genetics?
Answer:

• Gregor Johann Menclel worked on the problem of how variations were passed from one generation to the other.
• As he was a monk, he did his experiments with interest in the garden of the monastery.
• He worked for over seven years alter which he presented conclusions from his experimental data in a form of a detailed research paper.
• Mendel made many careful observations of pea plants and asked himself questions about what he observed and then planned and designed experiments to find the answers.
• He had worked on nearly 10,000 pea plants of 34 different varieties choosing 7 distinguishing forms of characters.
• His experimental outcomes gave the idea how the variations were passed on from one generation to another.
• He was an exemplary person for his observation, planning, patience and experimental skills.
• His efforts to know the secrets of nature was really appreciable.

Question 3.
How would you appreciate Charles Robert Darwin for his work on evolution?
Answer:

• Charles Darwin voyaged for five years, just when he was 22 years old.
• In the world survey ship H.M.S. Beagle, he visited number of places including Galapagos Islands.
• He keenly observed the flora and fauna of these places.
• He gathered a lot of information and evidences.
• He was influenced by the book “Principles of Geology” written by Sir Charles Lyell and “Maithus theory written in “An essay on the principles of population”.
• Darwin proposed the theory of “Natural selection”, means nature only selects or decides which organism should survive or perish in nature.
• This theory remained a milestone in the studies of evolution.
• Everyone should appreciate him for his observations and analytical abilities which revealed the secret from where we come from.

VII. Application To Daily Life, Concern To Biodiversity

Question 1.
Write a small essay supporting fila t genes are the cause to form to different characters in organisms.
Answer:
A gene is the section of DNA on a chromosome which controlls a specific characteristic of the organism. A gene is a unit of DNA on a chromosome which governs the synthesis of one protein that controls a specific characteristic of an organism. There are thousands of genes on a chromosome which control various characteristics of an organism.

Genes are actually units of heredity which transfer characteristics from parents to their offsprings (luring reproduction. Genes work in pairs. Genes controlling the same characteristics are given the same letters. For example the gene for tallness is represented by the latter ‘T’ whereas the gene for dwarfness is represented by the letter ‘t.

Genes for controlling the same characteristics of an organism can be of two types dominant or recessive. The gene which decider the appearance of an organism even in the presence of an alternative gene is known as dominant gene. The gene which can decide the appearance of an organism only in the presence of another identical gene called recessive gene.

Question 2.
Sujatha‘s in-laws worried for having daughter in her second delivery. How will you make them agree that she is not all responsible for having daughter
Answer:

• Sujatha is not responsible for giving birth to female child. Men are responsible for the birth of male / female child.
• Each human cell contains 23 pairs of chromosomes. Out of 23 pairs, 22 pairs of chromosomes are autosomes.
• The remaining pair is called allosomes or sex chromosome. These are two types; one is ‘X’ and the other is ‘Y’. These two chromosomes determine the sex of individual.
• Females have two ‘X’ chromosomes in their cells (XX). Males have one X’ and one ‘Y’ chromosome in their cells (XY).
• All the gametes produced by woman have only ‘X’ chromosomes. The gametes produced by a man are of two types one with X chromosome and other with ‘Y’ chromosome.
• If the sperm carries ‘Y’ chromosome and fertilizes the OVU (X chromosome). Then the baby will have ‘XY’ condition. So the baby will be a boy.

## TS 10th Class Biology Important Questions 7th Lesson Coordination in Life Processes

These TS 10th Class Biology Chapter Wise Important Questions 7th Lesson Coordination in Life Processes will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 7th Lesson Coordination in Life Processes

1 Mark Questions:

Question 1.
What happens if the direction of peristalsis is not reversed in animal like cow?
Answer:
If the direction of peristalsis is not reversed (rumination is not done) in animal like cow, the food will not be masticate in the mouth and fermentation of the food with the micro-organisms in the stomach will not be takes place.

Question 2.
What happens if the re is no mucus in the Oesophagus?
Answer:

• The walls of the food pipe secrete a slippery substance called mucus.
• Mucus lubricates and protects the oesophageal walls from damage.
• This helps the food bolus to slide down easily in the tube.
• If there is no mucus. lubrication will not done for the food bolus to slide and walls get damage.

Question 3.
Which part of small intestine absorbs digested food?
Answer:
Microvilli / villi.

Question 4.
Name the chemical which is used to test the action of saliva on flour (ata).
Answer:
Iodine Solution.

Question 5.
What happens, if there is no peristatic movement in Oesophagus?
Answer:

• The food won’t slidedown in the oesophagus.
• The digestion of food won’t takes place in the stomach and small intestine.

Question 6.
We remove our hand when we touch a hot subject. Find out its reflex action.
Answer:

Question 7.
When do we feel hunger fall pangs in stomach?
Answer:
When the level of glucose falls in the blood we feel hunger pangs in stomach.

Question 8.
Which hormone is responsible for hunger pangs in stomach?
Answer:
Ghrelin.

Question 9.
Which plays an important role in carrying hunger signals to brain?
Answer:
Diencephalon (forebrain) and vagus nerve (10th cranial nerve)

Question 10.
Increase in ghrelin levels results in?
Answer:
Sensation of hunger and motivation to consume food.

Question 11.
Which hormone suppresses hunger?
Answer:
Leptin.

Question 12.
interactions between what enhances our perceptions of the food we eat?
Answer:
Interactions between the senses of taste and smell.

Question 13.
What are the different types of papillae present on the tongue?
Answer:
Filiform papillae, fungiform papillae, phohate papillae and circumvallate papillae.

Question 14.
What is the dental formula of human beings?
Answer:
$$\frac{2,1,2,3}{2,1,2,3}$$ (present on one side of the jaw)

Question 15.
Name the different sets of teeth present in mouth.
Answer:
Incisors, canines, premolars and molars.

Question 16.
Write the number of different sets of teeth.
Answer:
Incisors -, 8, canines – 4, premolars – 8. molars – 12.

Question 17.
What is mastication?
Answer:
Grinding, chewing and shredding of food in the mouth by teeth is called mastication.

Question 18.
Which cranial nerve controls the movement of muscles in the jaw?
Answer:
Fifth cranial nerve (- Trigeminal nerve)

Question 19.
What is bolus?
Answer:
Food that is formed due to the mastication of food in the mouth is called bolus.

Question 20.
What is the function of salivary amylase?
Answer:
It breaks down the large starch molecules into smaller subunits usually into sugars.

Question 21.
What kind of tube is oesophagus?
Answer:
It is muscular and elastic.

Question 22.
How does mucus help in passage of food?
Answer:
Mucus lubricates, protects the walls from damage and helps bolus slide down easily to stomach.

Question 23.
What are the two kinds of muscles present in oesophagus
Answer:
Two kinds of smooth muscles are present – Inner layer consists of circular muscles and the outer layer of longitudinal muscles.

Question 24.
What is peristalsis?
Answer:
The involuntary contraction and relaxation of the muscles of oesophagus, stomach and intestine is called peristalsis.

Question 25.
What is chyme?
Answer:
The partly digested food in the stomach is called chyme.

Question 26.
What stimulates stomach muscle into action?
Answer:
Nervous system.

Question 27.
What causes the stomach to churn and mix the food?
Answer:
Peristalsis movements.

Question 28.
The muscles present at the opening of the stomach and the first part of the small intestine or duodenum?
Answer:
Pyloric sphincter.

Question 29.
Why should only a small quantity of food be passed from stomach to duodenum?
Answer:
For the complete digestion of the food.

Question 30.
What is involved in bringing about peristalsis?
Answer:
Autonomous nervous system.

Question 31.
What is the direction of peristalsis?
Answer:
It is forward direction from mouth it starts.

Question 32.
What happens if the direction of perista is reversed?
Answer:
Food moves in the backward direction.

Question 33.
What is the nature of the chyme?
Answer:
Acidic

Question 34.
Acidic nature of chyme initiates the production of hormones?
Answer:
Secretin and cholecystokinin.

Question 35.
Secretin and cholecystokinin stimulate
Answer:
Pancreas, liver and walls of small intestine to secrete pancreatic juice, bile juice and succus entericus.

Question 36.
What process is involved in the process of absorption?
Answer:
Selective absorption.

Question 37.
The parts that absorb nutrients from the food in small intestine?
Answer:
Finger-like projections called villi absorb nutrients.

Question 38.
Why do you think small intestine is long and coiled?
Answer:
For the remain of food longer thereby enhancing absorption.

Question 39.
What is second brain?
Answer:
The nervous system present below the gut or alimentary canal that control digestion is called second brain.

Question 40.
What is the other name for second brain?
Answer:
Enteric nervous system.

Question 41.
What controls the exit of stool from the body?
Answer:
Anal sphincter.

Question 42.
What happens during inhalation?
Answer:
During inhalation, oxygen moves across the walls of the alveoli and enters the blood.

Question 43.
What happens during exhalation?
Answer:
During exhalation, carbon dioxide from the blood moves into the alveoli of the lungs and breathed out.

Question 44.
What would be the path of salt removal from gut to the outside of our body?
Answer:
Sait is removed via through the kidneys. skin, etc.

Question 45.
For oxidation of for transport of substance which processes are to be coordinated?
Answer:
Respiration and blood circulation.

Question 46.
Why do you think the stomach is structured like a bag rather than a tube like oesophagus?
Answer:
The stomach is a muscular bag whose principal function in most groups is acidification and macerate ion of the food to the liquid state and temporary storage until it is passed to the intestine. Hence stomach is structured like a bag rather than a tube Like oesophagus.

Question 47.
How do we know that we need food?
Answer:
Hunger pangs are produced in our stomach due to the release of hormone Ghrelin.
This causes sensation of hunger and also we need food.

Question 48.
What could be the range of temperature for us to relish food items?
Answer:
41° F to 140° = F

Question 49.
Ritwik felt hunger pangs but could not take his meal on time. After some time the hunger pangs disappeared and he felt relieved. State the reasons.
Answer:
Ritwik felt hunger pangs due to release of hormone Ghrelin and hunger pangs disappeared due to release of hormone Leptin.

2 Mark Questions:

Question 1.
In the food pipe, the food bolas is propelled into the stomach by peristaltic movement. Represent this action with a diagram.

Question 2.
Take two similar green leaves. Apply grease on one leaf and leave the other free.
OR
Add 1 or 2 drops of acid on each lear What kind of change do you observe from this?
Answer:

• The leaf to which grease is applied is not effected with the acid.
• The leaf to which grease is not applied is effected.
• From the above activity we can conclude that mucus secreted by the walls of stomach protect it from the harmful effects of hydrochloric acid in the stomach.

Question 3.
Identify the diagram and write two functions of it.

Answer:
Liver:

• Breakdown of larger fats into small globules/emulsification of fats.
• It excretes Bile salts, cholesterol steroid, hormones, extra drugs, vitamins and alkaline salts through urine.

Question 4.
What will happen if islets of Langerhans fail to function?
Answer:

• Insulin may not be produced.
• Human may suffer from sugar diabetes.
• Sugar level increases in blood.

Question 5.
What may happen if villi are absent in small intestine?
Answer:

• Villi increase the surface area of the small intestine for absorption when food passes through it. If villi are absent, food will not be digested completely.
• Digested food will not be absorbed effectively.
• The food taken into the body is expelled out only after completing partial absorption in the small intestine.
• The body will suffer from starvation of nutrients.

Question 6.
Draw the diagram showing peristaltic movement. Write the names of the parts responsible for it.
Answer:

a. Mucus lubricates and protects the walls of oesophagus.
b. Circular muscles and longitudinal muscles of oesophagus help in the movement of food ‘bolus’.
c. Feristalsis is under the control of Autonomous nervous system.

Question 7.
How can the taste of food be detected?
Answer:

• On the tongue different types of papillae are present to sense different tastes.
• If we want to taste the food material, the food should be dissolve in saliva.
• We can taste the food that is in the form of liquid only.
• Only after the dissolved food enters into the cup-like taste buds (papillae), the sense of taste is carried tothe brain for analysis.
• Then only we will know the taste of the food material.

Question 8.
Write a short note on digestion of food in mouth.
Answer:

• In mouth, saliva is secreted by the action of autonomous nervous system to moisten the food to make chewing and swallowing easier.
• As a result of chewing food forms into a slurry mass called ‘bolus’.
• The enzyme salivary amylase in the saliva breaks down the large starch molecule into smaller subunits usually into sugars.
• During mastication food size becomes convenient to swallow.

Question 9.
Why do we salivate during a nap of (short sleep) daytime?
Answer:

• Nocturnal animals are active during nights but we are active during day time and take rest at night.
• All the systems of our body are active in function during the daytime of our activity. Hence, man is a diurnal animal.
• Our digestive system is also active and ready to receive the food for digestion.
• If we sleep during day time saliva oozes out of our mouth and wets the pillows.
• This will not happen during night time.

Question 10.
Explain the process of exit of waste materials from large intestine.
Answer:

• When the unwanted waste material reach the large intestine, the peristaltic waves move the stool into the rectum.
• Water gets reabsorbed and the remaining waste usually hard mass that gets stored in the last part of the large intestine i.e., the rectum.
• There are two muscular layers helping the exit of stools.
• One is under involuntary control and the other is under in voluntary control.
• These muscular structures help in opening and closing of the aperture of the canal which are called sphincter.

Question 11.
How do we detect the smell of agarbathi?
Answer:

• The fore brain is the main thinking part of the brain.
• It has regions which receive sensory impulses from various receptors.
• Separate areas of the fore brain are specialised for hearing, smell, sight and so on.
• Olfactory receptors send the information about the smell of incense stick to fore brain.
• The fore brain integrates it along with information received from other receptors as well as with information that is already stored in the brain.

Question 12.
Tooth enamel is one of the hardest substances in our body. How does it undergo damage due to eating chocolates and sweets?
Answer:

• The acid is formed in the mouth after a sugary food (chocolates and sweets) has been taken.
• This acid lowers the pH in the mouth.
• Tooth decay starts when the pH of acid formed in the mouth falls below 5.5.
• This is because then the acid becomes strong enough to attack the enamel of our teeth and erode it.

Question 13.
What do you think would happen if the salivary glands do not function in our mouth?
Answer:

• If the salivary glands do not function in our mouth saliva will not release in the mouth.
• Saliva is important to lubricate our mouth, help with swallowing, protect our teeth against bacteria and acid in the digestion of food. This will not occur as the saliva is not produced by salivary glands.

Question  14.
If we swallow food material directly without mastication, what will happen?
Answer:
If we swallow food material directly without mastication,

• Digestion process will not start.
• Makes the digestion process much complicated if the food is not made into bolus in the mouth.
• Absorption of nutrients from food is difficult.
• It will not promote feelings of fullness after eating

Question 15.
The mere smell or sight of food stimulates hunger. Describe the process in a flow chart.
Answer:

4 Mark Questions:

Question 1.
Give appropriate reasons for the below statements.

i. Hunger sensations reach brain when the stomach becomes empty.
Answer:
Ghrelin is secreted from walls of stomach.

ii. Hunger sensations stops after the stomach becomes full.
Answer:
Leptin hormone is secreted which supresses hunger.

iii. Food is not taste good when we suffer with cold.
Answer:
During cold olfactory receptors are blocked.

iv. We cannot identify the taste of grape when it is kept of tongue?
Answer:
We cannot taste the grapes because it is not in the liquid state.

Question 2.
Write the procedure involved in the acid and leaf experiment to understand the concept “how the stomach gets protected from its own acid secretions”. Compare the observations with the changes that takes place iii human digestive system.
Answer:

• Take two similar green leaves.
• Grease one leaf with petroleum jelly, leave the other free.
• Add 1 or 2 drops of some weak acids on both the leaves.
• Observe them after half-an-hour or so and write your observations.
• The leaf to which petroleum jelly was not applied effected by the acid.
• We observe the colour of the leaf changes.
• The other leaf was not affected by the acid because of petroleum jelly.

From the above activity we can conclude that mucus secreted by the walls of stomach protect it from the harmful effects of hydrochloric acid.

Question 3.
What is peristaltic movement? Compare the similarity of bolus movement in oesophagus with cycle tube and potato experiment which you have conducted in school.
Answer:
Peristalsis: Contraction and relaxation of circular and longitudinal muscles bring in a wave-like motion that propels the food bolus into the stomach from oesophagus by the action called as peristalsis.

Experiment:
Aim : Making a mode of oesophagus to observe how bolus moves forward.
Material required: Potatoes, cycle tube lubricate oil

Procedure:

• Take a piece of waste cycle tubes and insert one or two potatoes into it.
• Lubricate the inner side of the tube with oil.
• In the same way smear oil over potatoes.
• Insert oil coated potatoes in the tube.
• Now try to push the potatoes by squeezing the tube from behind the

Observation : Oil acted as lubricant to push the potato easily in the forward direction.
Conclusion : The muscles in the wall of the oesophagus have bring in a wave like movement due to contraction and relaxation, that propels the food bolus into the stomach. This action is called peristalsis.

I. Conceptual Understanding

Question 1.
Vasu is doing experiment, lab activities in his classroom. He is tired due to hungry. How does hungry feeling occur ? How will one know?
Answer:
Levels of different substances are generally maintained in the blood mainly by our digestive system. One of the major substance is glucose. When its levels in the blood fall, we get hunger pangs in stomach.

Ghrelin is secreted from the certain cells in the wall of the stomach. Hunger contractions (hunger pangs) start to occur in the stomach due to the secretion of Ghrelin hormone. Increase in ghrelin levels results in sensation of hunger and motivation to consume food.

Question 2.
Write about the experiment conducted by Ivan Pavlov on conditioned reflex.
Answer:

• Ivan Pavlov was a Russian scientist conducted experiments on conditioned reflexes.
• He discovered that dogs produced extra saliva when they were offered food.
• Pavlov noticed that they also did the same when the person who fed them came into the room, even if the person had not brought any food.
• Pavlov went on to ring a bell at the start of feeding time, and eventually the dogs produced extra saliva when they heard the bell, before any food was brought.
• A dog salivating when it hears a bell is not a natural response.
• They would not do this without being conditioned to do so.
• The behaviour has been learned. It is called a conditioned response.

Question 3.
Write briefly about the functional and structural aspects of oesophagus.
Answer:

• Oesophagus is a long muscular and elastic tube-like part of the digestive system which lies between pharynx and stomach.
• The wall of the oesophagus is made up of two kinds of smooth muscles.
• The inner layer consists of circular muscles and the outer layer of longitudinal muscles.
• The walls of the oesophagus secrete mucus, a slimy substance which helps in the easy movement of food into the stomach.
• Walls of oesophagus carry on wave-like movement by contraction and relaxation. These movements are known as peristalsis.
• Due to the peristalsis movements food passes from oesophagus into stomach.

Question 4.
Explain briefly about the structure of stomach.
Answer:

• Our stomach is not a bag with specific volume. It is a like a pouch which is elastic in nature.
• The size of the stomach increases based on the food we intake.
• Digestive juices are produced depending on the quantity of food material.
• The walls of the stomach secrete juice containing hydrochloric acid.
• Mucus secreted by some cells in the walls of the stomach form a thin lining on the walls of the stomach. This counters the action of acid.
• The food is thoroughly mixed with the digestive juices by peristaltic movements of muscles in stomach.
• The digestive juices of the stomach turn food into a smooth liquid mass called chyme.

II. Asking Questions and Making Hypothesis

Question 1.
‘Brain dead’ means 100% nonfunctioning of Brain. If you get a chance to meet any neurologist/Jeevandan volunteer, what questions you will ask about ‘brain dead’ patient?
Answer:
If get a chance to meet any neurologist, I will ask following questions.

• Will neurons of brain dead respire? or not?
• What about heart beat?
• Will heart beat take normally?
• Will blood circulate in the body or not?
• What is meant by ventilator?
• How much time does his (patient’s) organ survive after brain death?
• How much time is required to transplant brain dead patient’s organs?
• Which organs can transplant from brain dead?
• Is it necessary to match his blood group with recipient?
• Whom to consult to donate organs?
• Can anybody donate his organs?

III. Experimentation And Field Investigation

Question 1.
What is peristaltic movement ? Explain the food movement in alimentary canal comparing with the experiment of moving potatoes in cycle tube.
Answer:
Peristaltic movement is the contraction and relaxation of the muscles of the digestive system. The movement of food through food pipe is known as peristaltic movement.

Food movement in alimentary canal:

• The walls of the food pipe secrete a slippery substance called mucus. Mucus lubricates and protects the oesophageal walls, Irvin
• This helps the food bolus to slide down easily 3ust as the oiled potatoes that move in the tube. Oil acted as lubricant to push the potatoes easily in the forward direction.
• The wall of the oesophagus is made up of two kinds of smooth muscles. The inner layer consists of circular muscles and the outer laver of longitudinal muscles.
• Contraction of the circular muscles results in narrowing of the oesophagus just behind the bolus.
• So the food is squeezed downwards.
• Contraction of the longitudinal muscles in front of the bolus widen the tube, this results in shortening of that particular part of the oesophagus.
• Contraction and relaxation of these muscles bring in wave-like motion that propels the food bolus into the stomach by the action called as peristalsis.
• This is involuntary and under the control of autonomous nervous system.

Question 2.
How can you prove, show that stomach is protected from iron damage being caused by secretion of its own acid?
Answer:
Aim: How stomach is protected from damage being caused by secretion of it’s own acid.
Apparatus Required: Petroleum jelly, 2 leaves. Dil. acid dropper, petridish.

Procedure:

• Take 2 similar leaves.
• Grease one leaf with petrolium jelly leave the other tree. Keep then in a petridìsh.
• Add 1 or 2 drops of weak acid on both the leaves.

Observations:
After half an hour, leaf without greasing manages and leaf with greasing remain unchange.

Inference: Mucus secreted by some cell in the walls of stomach or a thin lining on the walls of stomach. This counter the action of acid. The function of petroleum jelly can be compared to that of mucus lining in stomach walls.

Hence the stomach is protected from damage being caused by the secretion of its own acids.

IV. Information Skills And Projects

Question 1.
Prepare a table information containing different kinds of teeth, number their shape and function.
Answer:

 S.No Name Of teeth Number Shape Function 1. Incisors 8 Chisel, sharp edges Biting 2. Canines 4 Sharp. Pointed edges Tearing 3. Prernolars 8 Diamond shape blunt and flat Chewing and grinding 4. Molars 12 Rectangular. blunt and flat Chewing and grinding

V. Communication Throught Drawing, Model Making

Question 1.
Draw peristaltic movement of food in stomach. Describe movement of food in stomach.

Answer:

• The stomach acts like a washing machine, churning the food around to break it into even smaller pieces.
• Mechanical mixing of food in stomach occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall.
• The contractions of the stomach muscles squeeze and mix the food with the acids and juices of the stomach.
• The digestive juices turns the food into smooth porridge-like consistency called chyme.
• As the process of digestion in the stomach nears completion, the contractions of the stomach decrease.

Question 2.
Describe with diagram how villi are helpful in absorption of digested food in small intestine.
OR
How is digested food absorbed in small intestine?
Answer:

• The small intestine is the main region for the absorption of digested food.
• The inner surface of the small intestine contains thousands of finger-like projections called villi
• These villi increase the surface area so that the food retained in the folds can remain longer thereby enhancing absorption.
• Blood vessels and lymph vessels are present in the form of a network in the villi.
• Products of digestion are absorbed first into the villi and from there into the blood vessels and lymph vessels.

## TS 10th Class Biology Important Questions 6th Lesson Reproduction

These TS 10th Class Biology Chapter Wise Important Questions 6th Lesson Reproduction will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 6th Lesson Reproduction

1 Mark Questions:

Question 1.
Give two examples of plants that are propagated by the cutting method.
Answer:

• Cutting Stems : Sugarcane, Roses, Hibiscus. Citrus plants.
• Cutting (Root) : Lemon. Tamarind.

Question 2.
How are cotyledons useful for the plant?
Answer:
Cotyledons have storage food for growing plant. until it forms the leaves.

Question 3.
In what way does mitotic division help the living organism?
Answer:
Mitotic division helps in

• growth
• cell repair
• healing wounds.

Question 4.
Give any two suggestions to create awareness to stop female foetlclde.
Answer:

• Preparing relevant slogans
• Organising rallies
• Awareness campaign by using electronic and print media

Question 5.
Write two precautions you take, while observing Rhizopus in the laboratory.
Answer:

• Don’t touch the experimental bread with hand.
• If you touch the bread, throughty wash your hands.
• Leave the bread in the open air for about an hour.
• Avoid opening of the plastic bag as much as you can.
• Sprinkle water over bread.
• Place the bag in a dark and warm place.

Question 6.
Mention two materials you have used to observe Rhizopus on bread mould.
Answer:
Bread mould sample, plain glass slide, cover slip, water, disposable gloves.

Question 7.
During favourable conditions paramoecium reproduce by?
Answer:
In favourable conditions paramoecium give rise to more of its kind from a single parent by simply splitting into two. (Binary fission)

Question 8.
In which organisms fragmentation is a common mode of reproduction?
Answer:
Algae, Fungi and many land plants.

Question 9.
What is parthenogenesis ? Give examples.
Answer:
Production of a new plant or animal from a female without the sexual involvement of the male is known as parthenogenesis. Eg: Watermelon, grapes.

Question 10.
What are the methods of artificial propagation?
Answer:
The methods of artificial propagation are Cutting. Layering and Grafting.

Question 11.
Which method is used to obtain a plant with desirable characters?
Answer:
Grafting is used to obtain a plant with desirable characters

Question 12.
What is tissue culture?
Answer:
In tissue culture, few plant cells or plant tissues are placed in growth medium with plant hormones in it and it grows into new plants.

Question 13.
What is the name of common bread mould?
Answer:
The name of common bread mould is Rhizopus.

Question 14.
What is fertilisation?
Answer:
Union of male and female gametes is known as fertilisation.

Question 15.
What is external fertilisation?
Answer:
If fertilisation occurs outside the body of the organism, it is known as external fertilisation. Eg: frog and fish.

Question 16.
What is internal fertilisation?
Answer:
If the fertilisation occurs inside the body of the female organism, it is known as internal fertilisation.
Eg: Terrestrial animals.

Question 17.
What are the parts that present in male reproductive system of man?
Answer:
A pair of testes, accessory glands and system of ducts.

Question 18.
What are the accessory glands present in male reproductive system?
Answer:
One prostrate, two cowper glands are present in male reproductive system.

Question 19.
What is ovulation?
Answer:
The release of ovum from graffian follicle is known as ovulation.

Question 20.
What is placenta?
Answer:
Placenta is the nourishment tissue formed by the cells of embryo and mother.

Question 21.
On which placenta is formed around?
Answer:
It is formed around 12 weeks of pregnancy.

Question 22.
What is the membrane that forms umbilical cord?
Answer:
A membrane called allontois, which originates from the digestive canal of the embryo forming the major part of a tube like structure called umbilical cord.

Question 23.
Whatis foetus?
Answer:
From the third month of pregnancy the embryo is called foetus.

Question 24.
What is gestation period?
Answer:
Total time required for the development of embryo and foetus is called gestation period.

Question 25.
What is the gestation period in human beings?
Answer:
It is 9 months or 280 days.

Question 26.
What are labour pains?
Answer:
The rythemic contraction and relaxation of muscle layers of the uterus is known as labour pains.

Question 27.
What is the need of sexual reproduction?
Answer:
Sexual reproduction help organisms to develop characters that would be help them to adapt better to their surroundings.

Question 28.
What are the different parts of a flower?
Answer:
Sepals, petals, stamens and carpels are the different parts of a flower.

Question 29.
What are unisexual flowers?
Answer:
Flowers containing either stamens or carpels are called unisexual flowers. Eg: Bottlegourd, papaya.

Question 30.
What are the three parts of carpel?
Answer:
Stigma, style and ovary are the three parts of carpel.

Question 31.
What is self pollination?
Answer:
Plants having flowers where reproductive cells of stamen of the flower fertilise the female reproductive cells of the carpel of the same flower is called self-pollination. Eg: Plants of pea family.

Question 32.
What is cross pollination?
Answer:
Pollen grains of a flower are transferred to the stigma of a flower of another plant of the same species, is called cross pollination.

Question 33.
What is double fertilisation?
Answer:
Union of one pollen tube nucleus with the egg and the second pollen tube nucleus with the fusion nucleus is called double fertilisation.

Question 34.
Who discovered mitosis?
Answer:
Waither Flemming of Germany discovered mitosis in 1879.

Question 35.
What is the meaning of the phase “Omnis cellula de cellula”?
Answer:
It means cells arise from pre existing cell.

Question 36.
Cells in which organism do not divide?
Answer:
Heart and Brain.

Question 37.
What is interphase?
Answer:
The period between two cell divisions is called interphase.

Question 38.
What is G2, phase of the interphase?
Answer:
This is linking period between the completion of mitosis and the beginning of DNA replication. The cell size increase during this period.

Question 39.
What Is ‘S’ phase of the interphase?
Answer:
This is the period of DNA synthesis leading to duplication of chromosomes.

Question 40.
What is ‘G2’ phase of the interphase?
Answer:
This is the time between the end of DNA replication and the beginning in mitosis

Question 41.
What are the different stages present in mitosis?
Answer:
Prophase, Metaphase, Anaphase and Telophase are the stages present in mitosis.

Question 42.
When does meiosis occur?
Answer:
Meiosis occur only during the formation of gametes in sexual reproduction.

Question 43.
What is the virus that causes AIDS?
Answer:
Human Immuno deficiency Virus (HIV).

Question 44.
How does AIDS spread from one person to another?
Answer:
This disease spread by unsafe sexual contacts using infected devices, infected blood transfusion from an infected mother to child.

Question 45.
What are the factors that contribute to the spread of HIV in the state?
Answer:
Illiteracy, poor health, unemployment, migration, non-traditional sex practice, unethical contacts and traffiking are some of the factors that spread HIV.

Question 46.
What is contraception?
Answer:
The prevention of pregnancy in women by preventing fertilisation is called contracention

Question 47.
What are the surgical methods to prevent fertilisation?
Answer:
Vasectomy and Tubectomy are the surgical methods to prevent fertilisation.

Question 48.
What is the marriage age for girl child?
Answer:
18 years.

Question 49.
What Is foeticide?
Answer:
Foeticide is the act of destruction or aborting a foetus because it is female. (Or) Medical Termination of Pregnancy (MTP)

Question 50.
Who used cell fusion technique to understand the functional relationship between different phases of interphase?
Answer:
Potu Narasimha Rao and Johnson.

Question 51.
Give examples for sexually transmitted diseases.
Answer:
Gonorrhoea, syphilis, AIDS and herpes, etc.

Question 52.
What is the advantage of reproduction through spores in the case of rhizopus?
Answer:
The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

Question 53.
Which process taking place in the nucleus of a cell leads to variation in the offspring during reproduction?
Answer:
DNA copying.

Question 54.
Why is if said that sexual reproduction promotes diversity of characters in the offsprings?
Answer:
It is because sexual reproduction results from the fusion of two gametes coming from two different and sexually distinct indMduals. This leads to variation i.e.. necessary for evolution.

Question 55.
Name the causative organism of syphilis and gonorrhoea.
Answer:
Syphilis is caused by Treponema pallidum and gonorrhoea is caused by Nisseria gonorrhoea.

Question 56.
Why are variations possible in progeny of sexually reproductive individuals?
Answer:
Variations are possible in progeny of sexually reproductive individuals because copy of DNA in newly formed cell is not identical to copy DNA of original cell.

Question 57.
The simple animals such as planaria can be cut into number of pieces and each niece grows into a complex organism. What is this process known as?
Answer:
Regneration.

Question 58.
A student kept leaves of Bryophyllum in the soil. After a few days new plants were grown from them. why?
Answer:
Bryophyllum leaves bear buds in their notches along the margin. When a leaf kept in the soil, the buds come in contact of the soil and develop into plantlets. These plant-lets later grow into new plants.

Question 59.
Name the three plants which are now grown using plant tissue culture method.
Answer:

• Orchids
• Chrysanthemum
• Asparagus

Question 60.
What does the mother’s blood take away from the baby and into the placenta?
Answer:

• The mother’s blood takes away waste products like carbon dioxide and waste materials such as urea, uric acid and creatinine from the baby.
• The mother’s blood supplies oxygen and nutrients to the baby through placenta.

2 Mark Questions:

Question 1.
Write any four slogans for propaganda against female foeticide.
Answer:

• Stop female foeticide — Save the girl child.
• Without girl child there is no life.
• Todays girls are tomorrows ideal leaders.
• Girls are the wealth of the society.
• If girls become rare — what about our care.
• Beti bachavo — Beti padavo
• Female foeticide is a crime — Don’t commit it at any time.

Question 2.
Identify the flower parts a, b, c, d and write their main function.
Answer:

• Ovary : Female reproductive organ in flower. It produce female gametes called ovules.
• Style : Ovary has a pipe like structure called style. It allows the pollen tube to enter the ovary for fertilization.
• Stamen : These are male parts called androecium. It has two parts. They are filament and Anther.
• Anther : Produces male gametes called pollen grain.

Question 3.
Draw and label the diagram of human sperm cell.
Answer:

Question 4.
How will we get the desired useful triats with the help of two selected triats by using grafting method?
Answer:

• Two plants are joined together in such a way that two stems join and grow as a single plant.
• One which is attached to soil is called stock and the cut stem of another plant without roots is called scion.
• Both stock and scion are tied with the help of a twine thread and covered by a polythene cover.
• Grafting is used to obtain a plant with desirable characters.
• This technique is very useful in propagating improved varieties of plants with various flowers and fruits.
Ex : Mango, citrus, apple, rose.

Question 5.
Draw the labelled diagram of Embryo-sac.
Answer:

Question 6.
Observe the diagram and answer the following questions.
i. Which phases take sanie time duration?
Answer:
G1 phase and S phase.

ii. In which phase, DNA synthesis takes place?
Answer:
S Phase.

Question 7.
Write the process involved in seedless fruit development with two suitable examples.
Answer:
In some plants ovary directly develops into fruit without the process of fertilization this phenomenon is called as parthenocarpy. Ex: Grapes, watermelon.

Question 8.
What precautions will you take to keep away from diseases like AIDS and other sexually transmitted diseases?
Answer:

• Avoid sex with unknown partners or multiple partners.
• Use condom every time.
• Use disposable syringes and needles.
• Transfusion of safe blood to the patients.
• HIV mother can have child with doctor’s advice only.

Question 9.
Observe the diagram and answer the following questions.

i. Name male and female reproductive parts of the above figure.
Answer:
Male reproductive parts – anther / pollen grain / stamen
Female reproductive parts – ovary / ovule / style / stigma.

ii. Write the names of (1) and (2) In the diagram.
Answer:

1. Sepal or calyx
2. Petal or corolla

Question 10.
When does Parthenogenesis occur? Write names of two animals in which parthenogenesis takes place.
Answer:

• Parthenogenesis is a process of reproduction where there is a shift from sexual to asexual mode of reproduction.
• In this process generally the female gamets develops into zygote without fertilization.
• This strange kind of reproduction occur in bees, ants and wasps.
• The parthenocarpic zygote develop into male (Monoploid) while the fertilized one developed into female (Diploid)

Question 11.
Draw the figure of metaphase in mitosis, and write about it.
Answer:

• Chromosomes move to spindle equator, centromeres attached to spindle fibres.
• Centrorneres split, separating the chromatids.

Question 12.
Prepare 4 questions on meiosis, to conduct a Quiz programme.
Answer:

• Where does meiosis occurs in?
• How many daughter cells are produced at the end of meiosis?
• In which phase of meiosis karyokinesis takes place?
• Name the scientist who discovered meiosis for the first time.

Question 13.
Write slogans on ‘Oaild marriages – a social evil’.
Answer:

• Child marriage — A losing game.
• She is a child herself, why burden her with another child?
• My childhood — My right.
• A child should call ‘mother’ but a child should not be called mother.
• Good marriages take place slowly. Go slow with children’s marriage.
• Say no to child marriage.

Question 14.
Write 5 slogans on the prevention of HIV/AIDS.
Answer:

• Open your eyes before Aids closes them.
• late the disease but not the diseased.
• Spread the knowledge not the virus.
• Wear protection to prevent infection.
• AIDS brings pain ! Girls please abstain.

Question 15.
Write briefly about natural vegetative propagation.
Answer:

•  In natural vegetative propagation new plants are produced from stem, root, leaves of old plants without the help of any reproductive organs.
• In bryophyllum small plants grow at the edge of leaves.
• Aerial weak stems like runners stolons, when they touch the ground give it adventitious roots.
• When the connection with the parent plant is broken the stem portion with the adventitious roots develops into an independent plant.
• Some examples for propagation by stem are from stolons, bulbs. corms, tuber, etc.

• Stolon — Vallisner . strawberry.
Bulbs — Onion AIIiumcepa)
Corms — Colacasia, Ginger
Tuber — Potato
Root — Radish. Carrot, etc.

Question 16.
What is the present scenario of HlV infection in Telangana and Andhra Pradesh?
OR
What are the causes for HIV infection?
Answer:

• Telangana and Andhra Pradesh has the highest number of HIV positive patients in the country.
• According to official statistics, the state had 24 Lakh HIV positive patients in the country during 2011 – 12.
• The prevalence of HIV is 1.07 percent among males and 0.73 among females in the state, which again is higher than other states.
• HIV prevalence among adults (15 – 49 years) 0.90 percent, pregnant women 1.22 percent in Andhra Pradesh.
• Illiteracy, poor health, unemployment, migration, non-traditional sex practise, unethical contacts and trafficking are some of the factors contributing to the spread of HIV in the state.

Question 17.
What are sexually transmitted diseases and mention the ways to prevent them?
Answer:
1. A disease which can be transmitted through sexual contact is called sexually transmitted disease or STD.
2. These include bacterial infections such as gonorrhoea, syphilis and viral infections such as herpes and AIDS.
3. Lack of hygiene is usually a major factor in providing conditions for spread of STDs.
4. But unprotected sex with multiple and unknown partners is the highest reason for the spread of STDs.
5. Some of the ways to prevent STD are as follows.

• Being faithful to one’s life partner.
• Avoid sexual contact with unknown person.
• Using condom during sexual intercourse.
• Maintaining personal hygiene.

Question 18.
Why can more complex organisms not give rise to new individual through regeneration?
Answer:

• Many organisms have the ability to give rise to new individual organisms from their body parts.
• Regeneration happens through mitosis and a particular type of tissue can give rise to its own kind only.
• In complex organisms, different tissues and organs have altogether different structures.
• Regenerating a different kind of tissue from another kind is not possible.
• Hence complex organisms are not able to give rise to new individuals through regeneration.

Question 19.
What are the advantages of vegetative propagation?
Answer:

• Vegetative propagation helps to maintain fixed qualities and characteristic features of the parent plant.
• It takes less time to grow plant through vegetative propagation.
• Vegetative reproduction offers a uniform root stock for budding and grafting. This root stock can be selected from a plant that is immune to diseases.
• In vegetative propagation it would be possible to develop new varieties with useful characters.
• Vegetative reproduction is a very useful method of reproduction in plants that rarely produce flowers.

Question 20.
How will an organism be benefited if It reproduces through spores?
Answer:

• Reproduction through spores gives several advantages to an organism like they are produced in very large numbers and it helps in propagation of species.
• Spores can remain dormant till favourable conditions become available.
• Spores help an organism to overcome unfavourahie conditions.
• Spores can be spread through water, air or animals and thus is good for the spread of an organism to more places.

Question 21.
What is the role of placenta in embryo development?
Answer:

• Placenta is a tissue formed by the cells from the embryo and the mother.
• It is formed at around 12 weeks of pregnancy and becomes an important structure for nourishment of the embryo.
• Placenta is a disc which is embedded in the uterine wall. It contains villi on the embryo’s side of the tissue.
• On the mother’s side are blood spaces.
• This provides a large surface area for diffusion of glucose, oxygen and other nutrients from the mother of the embryo.

Question 22.
What causes joining up of stock and scion grafting technique of vegetative propagation in plants?
Answer:

• The stock and scion unite due to cambial cavity.
• Stock is the portion on which the grafting is done and it provides the roots.
• Scion is the portion of the plant which is grafted on the other plant and it contributes the stem.
• The plant contributing scion should have large sized fruits and the plant contributing stock should have deep root system.

Question 23.
How does binary fission differ from multiple fission?
Answer:

 Binary fission Multiple fission 1. No protective coat or wall or cyst is formed around the cell. 1. A cyst or a protective coat or wall is formed around the cell. 2. A fully mature individual cell divides into two producing two daughter individuals. 2. The cell nucleus divides many times within the cyst to produce many daughter nuclei. Each gathers cytoplasm and forms daughter individuals. 3. No such phenomenon occurs. 3. The parent cell breaks away, releasing many individuals at once.

Question 24.
Why is DNA copying an essential part of the process of reproduction?
Answer:

• DNA is the genetic material which makes proteins which in turn give rise physical characteristics of an organism.
• Copying of DNA results in transfer of information to form a fully developed organism.

Question 25.
Differentiate between asexual reproduction and sexual reproduction.
Answer:

• Asexual reproduction involves only a single individual. It does not require two sexes.
• Sexual reproduction involves two different individuals, male and female sexes. The offspring is produced due to fusion of male and female gametes.

Question 26.
Differentiate between unisexual and bisexual flower. Give two examples of each.
Answer:

• When a flower contains either stamens or carpels it is said to be unisexual. Examples: Papaya and watermelon.
• When a flower contains both stamens and carpels it is said to be bisexual. Examples: Hibiscus and mustard.

Question 27.
How is the process of pollination different from fertilization?
Answer:

• Pollination is the process by which the pollen from another reaches the stigma of the flower of the same species.
• Fertilisation is the process in which the male gamete fuses with the egg to form zygote.

Question 28.
If a woman is using a copper-T will it help in protecting her from sexually transmitted diseases?
Answer:

• Copper-T is a contraceptive method which prevents implantation of the zygote inside the uterus.
• It cannot prevent a woman from sexually transmitted diseases.
• Sexually transmitted diseases are transmitted by contact which cannot be prevented by copper-T.

Question 29.
Arjun Tendulkar injured his knees while fielding at ground. The injury was healed after some days. Arjun was eager to know the process behind it. Describe the process involved in wound healing.
Answer:

• The process behind healing of wounds of Arjun is mitosis.
• Due to mitosis cuts, bruises and injuries heal themselves in a few days.
• Cells present at the margins of wound divide repeatedly by mitosis and the resulting daughter cells fill the wound once the entire wound is filled up these cells stop dividing.

Question 30.
Why is vegetative propagation practised for growing some types of plants?
OR
Why is vegetative propagation adopted over other types of propagation ?
Answer:
Vegetative propagation is practised in some plants because

• It is the only method of reproduction in seed less plants.
• We get more number of matured plants in a very short time.
• Thousands of plants can be grown in very short time.
• This method can help the breeder in preserving the characters he need.
• It is very easy and economical method for the multiplication of ornamental plants.

Question 31.
Chromosomal number is reduced to half in the daughter cells produced by meiosis. What happens if the number is not reduced to half in daughter cells?
Or
In Meiosis, the chromosome number in the daughter cells are reduced to half that of their parent cells. Guess, what would happen, If the reduction of
chromosome number is not done.
Answer:

• If the reduction of chromosomes number is not done, the chromosomal number is doubled in the offsprings.
• The change in chromosomal number changes completely the characters in the individual
• The offspring differs to parental generation.
• Abnormal characters will be formed in new generation, which are not useful for the existence of individual.

Question 32.
What are the questions you asked the doctor who visited your school to know “the ways of transmission of HIV” ?
Answer:
I shall ask the following questions to the doctor.

• What are the ways of transmission of HIV?
• How, can we prevent the spread of HIV?
• What precautions should we take while doing transfusion of blood?
• How does HIV transmit from mother to baby?
• Why should we use disposable syringes?

4 Mark Questions:

Question 1.
Describe the life cycle of a flowering plant with a help of neat labelled diagrams.
OR
Draw the life cycle of a flowering plant.
Answer:
1. Adult plant produces flowers:
When the plant matures and is ready to reproduce, it develops flowers. Flowers are special structures involved in sexual reproduction, which includes pollination and fertilisation.

2. Pollination: The transfer of pollen grains from the anther of a stamen to the stigma of a carpel is called pollination.

3. Fertilisation:

• After pollen grains falls on the stigma fertilization occurs when the male gamete
present in pollen grains joins with the female gametes present in the ovule.
• In the ovary the male gamete of pollen combines with the nucleus of female gamete or egg present to form zygote.

4. Formation of fruit and seed: After fertilisation, a combined cell i.e. zygote grows into an embryo within a seed formed by the ovule.

5. Each seed contains a tiny plant called an embryo which has root, stem and leaf parts ready to grow into a new plant when conditions are favourable.

6. Another part of the flower (the ovary) grows to form fruit, which protects the seeds and helps them spread away from the parent plant to continue the cycle.

Question 2.
Analyze the following information and answer the following questions.
Answer:

 S.No Name of the plant Method of propagation 1. 2. 3. 4. 5. 6. Mango Rose, Hibiscus Jasmine Bryophyllum Colacasia Onions Grafting Cutting Layering Small plants grow on edges of leaves Corms Bulbs

i. What do you call the given reproduction methods?
Answer:
Given reproduction methods are called ‘vegetative propagation’.

ii. What is the major difference between sexual reproduction and vegetative reproduction in plants?
Answer:
In sexual reproduction gametes formed zygote. But it is not seen in vegetative reproduction. It is one of a sexual method.

iii. Potato plants do not produce seeds. How can you propagate this plant?
Answer:
Potato plants propagates through the ‘eyes’.

iv. What are the advantages of propagating plants with the above given methods?
Answer:
In vegetative propagation

• More plants are produced in less time
• Characters are not changed.
• It would be possible to develop new varieties with useful characters.

Question 3.
Explain the methods of artificial propagation in various plants.
Answer:
Artificial propagation:

1. Cutting : Some plants can grow individually when a piece of the parent plant having bud is cut off from the existing plant. The lower part of this cutting is buried in moist soil. After few days the cut parts having buds grow as an individual plant after developing roots. E.g. Rose, Hibiscus.

2. Layering : A branch of the plant with atleast one node is bent towards the ground and part of it is covered with moist soil. After a few days new roots develop from the part of the branch buried in the soil. The branch is then cut off from the parent plant. E.g: Nerium, Jasmine

3. Grafting : Two plants are joined together in such a way that two stems join and grow as a single plant. This technique is very useful in propagating improved varieties of various flowers and fruits. Grafting is used to obtain a plant with desirable character. E.g: Mango, citrus, apple, rose.

Question 4.
Mention the stages of Mitosis with the help of diagrams. Explain the changes that takes place in Prophase.
Answer:
Mitosis is a method of cell division, in which the nucleus divides into two daughter nuclei each containing the same number of chromosomes as the parent nucleus mitosis takes place in all body cells which retains same number of chromosomes.

Different stages of mitosis:

• Prophase
• Metaphase
• Anaphase
• Telophase

Prophase : In this phase chromosomes condense and get coiled. They become even in light microscope and nucleoli becomes smaller. Chromosome split lengthwise to form chromatids connected by centromeres. Nuclear membrane breaks down. Centrosome containing rod like centrioles, divide and form ends of spindle.

Question 5.
Describe the process of double fertilization in plants. Explain the uses of endosperm that is formed.
Answer:
Double fertilization: In flowering plant germinated pollen rain forms pollen tube. The end of the pollen tube ruptures and two male gamets are released in the Embryosac. Out of two male gamets one male garnet fuses with female garnet which is called fertilization another male garnet fuses with the secondary nucleus and forms endosperm so in flowering plant fertilization occurs twice hence it is called double fertilization.

Uses of Endosperm:

• Cotyledons develop by utilizing endosperm.
• The cotyledons utilize the stored food in the endosperm.
• Some of the plants utilize the endosperm completely and change into seed.
• Because of the stored food the size of the cotyledons increases.

Question 6.
Read the following table and answer the following questions.
Answer:

 SI. No. Structure Location 1. Tricuspid valve Right auriculo-ventricular aperture 2. Guard cells Epidermis of leaves 3. Glomerulus Nephron 4. Alveoli Lungs 5. Acrosome Above the head of a sperm.

i. Name the structure concerned to the heart.
Answer:
Tricuspid valve

ii. What is the function of acrosome?
Answer:
It helps the sperm in penetrating into ovum.

iii. Name the structures which are helpful for gaseous exchange.
Answer:
Alveoli and guard cells

iv. Name the part performing Excretion.
Answer:
Glomerulus

Question 7.
Explain any two natural and two artificial vegetative propagation methods to produce more number of plants In less time period with examples.
Answer:
Natural propagation:
i. Leaves – Small plant grow at the edge of the leaves. Ex: Bryophyllum
ii. Stems:

• Stolon – Ex : Jasmine, strawberry
• Bulbs – Ex : Onion
• Corns – Ex: Colocasia
• Rhizome – Ex : Ginger
• Tuber – Ex: Potato

iii. Root – Ex: Roots of murayya, guava

Artificial propagation:
Cutting: Some plants can grow individual when a piece of parent plant having bud is cut off from the existing plants.
Ex: Rose, Hibiscus.

Layering: A branch of the plant with at least one node is bent towards the ground and a part of it is covered with moist soil leavings the tip of the branch exposed above the ground. Ex: Nerium, Jasmine.

Grafting: Two plants are joint together in such a way that stems join and grow as a single plant one which is attached to soil is called stock and stem of another plant without roots is called scion. Both stock and scion are tied with a twine thread and cover by a polythene cover. Ex: Mango, citrus, apple, rose.

Question 8.
Observe the following table.

 Reproduction system Organisms Fission Paramoecium, Bacteria Budding Yeast, Hydra Fragmentation Flatworms, Spirogvra Rhizome Ginger, Turmeric Cutting Rose, Hibiscus Grafting Citrus, Apple

On the basis of information given In the table write the answers to following questions.

i. Write the names of two organisms that show Asexual reproduction.
Answer: Yeast, Hydra, Bacteria, Paramoecium (any two you may write)

ii. Write two artificial vegetative propagation methods mentioned in the table.
Answer: Cutting, Grafting

iii. Write the names of two plants, which undergo natural vegetative propagation mentioned in the table.
Answer: Ginger, Turmeric

iv. In fission, how many organisms can we get from one organism?
Answer: Two

I. Conceptual Understanding

Question 1.
Among the following organisms can we see asexual reproduction? Write about the method of asexual reproduction in any of the two organisms.
a. Paramoeclum
b. Yeast
c. Spirogyra
d. Amoeba
e. Planaria
Answer:
Yes, we can see asexual reproduction in all the following organisms.

• Method of asexual reproduction – Organism
• Binary fission – Paramoecium, amoeba
• Budding – Yeast
• Fragmentation – Spirogyra
• Regeneration – Planaria

1. Binary fission In Paramoeclum : A single cell divides into two equal daughter cells. First the cytoplasm divides into two parts followed by nuclear division.

2. Asexual reproduction in Yeast : Budding is the common method of asexual reproduction in yeast. In this method, yeast cell wall at a particular region becomes soft and bulges into an outgrowth called bud. Cytoplasm enters into this bulge and then nucleus divides mitotically into two nuclei, one moves into the bud. Finally bud is detached from the parent cell and grows into an independent yeast cell.

Question 2.
See the adjacent picture. Which type of pollination will occur in this? Why do you think so?
Answer:
Self pollination occurs if stamens and carpels matures at the same time. If they mature at different times cross pollination occurs. Cross pollination occurs in this plant. For cross pollination to occur the pollen grains are to be carried to from other plants belonging to the same species.

The mechanism of dispersal of pollen grains from one plant to other plant is facilitated mostly by wind and insects. Cross pollination is believed to be advantageous for the plant because the seeds produced by the flower will contain another source of genetic material which may contain genes which are advantageous to the survival of the seedlings.

Question 3.
Describe different artificial vegetative methods to produce large scale production of plants.
Answer:
1. Different artificial vegetative propagation methods are cutting, layering, grafting and tissue culture methods.

2. Culling : Some plants grow individually when a piece of parent plant having bud is cut from the existing plant. After burying in the soil the cut parts having buds grow as an individual plant after developing roots. E.g. Rose.

3. Layering: A branch of the plant with at least one node is bent towards the ground and part of it is covered with moist soil. After sometime, new roots develop from the part of the branch burned in the soil. The branch is then cut off from the parent plant. E.g: Nerium, Jasmine.

4. Grafting: Two plants are joined together in such a way that two stems join and grow as a single plant. This technique is very useful in propagating improved varieties of various flower and fruits. Grafting is used to obtain a plant with desirable character. E.g : Mango. citrus, apple, rose.

5. Tissue culture: In this method, few plant cells or plant tissues are placed in a growth medium with plant hormones in it and it grows into new plants. Thousands of plants can be grown in very short Interval of time.

Question 4.
i. Labelled parts of A, B, C, D above drawn Human female reproductive system.
ii. In which part ferifiization takes place?
iii. Which part is in connection with Implantation?
iv. What is ovulation?
Answer:
i.

• A : Fallopian tube
• B : Ovary
• C : Uterus D : Vagina

ii Fertilization takes place in fallopian tube.
iii. Uterus
iv. Release of ovum from graffian follicle of ovary is known as ovulation.

Question 5.
Write the differences between asexual reproduction and sexual reproduction.
Answer:
a. Asexual reproduction – Sexual reproduction:

 Asexual reproduction Sexual reproduction 1. Involves single organism. 1. Involves one or two organisms. 2. No production of gametes. 2. Male and female gametes are produced. 3. There is no fusion of gametes. 3. It involves fusion of male and female gametes. 4. It requires only mitotic divisions. 4. It requires meiotic division followed by mitotic division. 5. It produces offsprings that are identical to the parent. 5. Offspring will have some characters from male parent and others from female parent. Some characters may not be present in either of the parents. 6. In this chance of genetic variation is only through random mutation. 6. In this reproduction there is more chance for genetic variation. 7. Asexual reproduction is not very useful for natural selection in evolution of species. 7. Sexual reproduction is highly useful for natural selection in evolution of species. 8. It occurs by budding, fragmentation, sporulation. 8. It occurs due to pollination and fertilization.

Question 6.
Briefly explain about artificial vegetative propagation.
OR
Describe about cutting, layering and grafting in vegetative propagation.
Answer:
1. The process of growing many plants from one plant by man-made methods is called artificial propagation of plants.
2. The three common methods for the artificial propagation of plants are :

• Cutting
• Layering and
• Grafting.

a. A small part of a plant which ¡s removed by making a cut with a knife is called cutting. A cutting may be a piece of stem, root or even to a leaf. Eg: Rose, Bougainvillia, Sugarcane, Banana, etc.

b. In Layering a branch of the plant with at least one node is bent towards the ground and a part of it is covered with moist soil leaving the tip of the branch exposed above the ground. After some time, new roots develop from the part of the branch buried in the soil. The branch is then cut off from the parent plant. Ex : Nerium, Hibiscus.

c. In grafting two plants are joined together in such a way that two stems join and grow as a single plant. Eg: Mango, Citrus, Apple, Rose etc.

Question 7.
Describe the structure of male reproductive system in human beings. With neat labelled diagram explain the structure of male reproductive system in human beings.
Answer:

• The male reproductive system of human beings consists of a pair of testes, accessory glands and a system of ducts.
• Testes are male reproductive organs and produces spermotozoa or sperms and also secretes male sex hormone Testosterone.
• Inside each testis several lobules are present. Each lobule has several tubules called seminiferous tubules.
• Germinal epithelial cells in the seminiferous tubules undergo meiotic division to produce spores.
• The accessory glands include one prostrate gland and two cowper glands. Secretion of these glands produce semen.
• The duct system consists of vas efferentia. They collect spermatozoa from seminiferous tubules.
• Vasefferentia continue as epididymis where sperms are stored temporarily.

Question 8.
Describe briefly about the female reproductive system in human beings.
Answer:

• A pair of ovaries are the reproductive organs in woman.
• They are present just below the kidneys in the abdominal cavity.
• Each ovary has severed sac like structures called ovarian follicles or Graffian follicles.
• Every time only one follicle matures and releases one ovum into body cavity.
• Just above the ovaries are the tubes called oviducts or fallopian tubes.
• The two oviducts connect to a bag like organ called uterus at their other ends.
• The uterus is connected through a narrow opening called cervix to another tube called vagina which opens to the outside of the body.
• Vagina is a tubular structure and is also called birth canal because it is through this passage that the baby is born after the completion of development inside the uterus of the mother.

Question 9.
Write a short note on child birth.
Answer:

• Total time required for the embryonic and foetal development is about 9 months or 280 days.
• After this time, foetus is expelled from the uterus by the mother. This is child birth.
• Child birth is a complicated process and involves the participation of child and mother.
• The foetal hormones produced inside, stimulate the contraction of the muscles present in the walls of uterus.
• These contractions called labour pains help in the expulsion of the foetus from the uterus.
• During this process the amnion ruptures, placenta is separated from the walls of the uterus.
• At child birth the head usually comes out first.
• The foetus is still attached to the mother’s uterus through the umbilical cord, which is later separated by the doctors.

Question 10.
Describe the structure of flower with a neatly labelled diagram.
Answer:

• A typical flower consists of an outer whorl of green sepals (calyx. which protects the parts within.
• The second whorl has petals (corolla. which are usually brightly coloured. They sometimes have fragrance also.
Petals are soft and are useful to attract insects to facilitate cross pollination.
• The third whorl of the flower consists of stamens Androecium. which are the male reproductive organs.
• Each stamen is made up of a filament and an anther.
• Each anther usually has two anther lobes. The anther produces pollen grains microspores.
• The inner most fourth whorl is gynoecium or pistil. It consists of ovary, style and stigma.
• Ovary occupies central portion on the thalamus. A swollen ovary is present on the thalamus.
• Inside the ovary future seeds, known as ovules are present.
• Ovary has a pipe like extension called style. The tip of the style ends in stigma. The stigma receive the pollen grains.

Question 11.
Describe briefly about the meiosis or reduction division.
Answer:

• Meiosis occurs only during the formation of gametes in sexual reproduction.
• During meiosis only one set of chromosomes are passed on to the daughter cells. Hence daughter cells have half the number of chromosomes of the mother cells.
• In meiosis karyokinesis and cytokinesis occur two times.
• During first phase of meiosis the parent cell divides twice, though the chromosomes divide only once.
The second phase meiosis is similar to normal mitosis, but chromosomes do not duplicate, more over the chromosomes are distributed equally to each cells.

• Thus the four daughter cells have just half the number of chromosomes of the parent cells.
• These are haploid (containing only one set of chromosome.
• Thus meiotic division is also called reduction division.

Question 12.
What is contraception ? What are the contraceptive methods followed for birth control ?
Answer:

• The prevention of pregnancy in women by preventing fertilisation is called contraception.
• Any device or chemical (drug. which prevents pregnancy in woman is called contraceptive.
• Physical devices such as condoms and diaphragm (cap. are used. This prevents reaching of sperms to ova for fertilisation.
• Chemicals in the form of pills are induced either orally or inserting into female reproductive organ vagina.
• Pills for males kill the sperms and hence are called spermicide.
• The use of intra – uterine device called copper – T, loop, etc. are also very effective in preventing pregnancy.
• Surgical methods of birth control are available for males as well as females.
• In males a small portion of vas deferens sperm duct. is removed by surgical operation and both ends are tied properly. This method is called Vasectomy.
• In females a small portion of oviducts (fallopian tubes. is removed by surgical operation and the cut ends are tied. This method is called Tubectomy.

Question 13.
Describe the developmental stages of human embryo after fertilization.
Answer:

• During fertilization, chromosomes of the ovum and the chromosomes of the sperm make up into pairs and the resulting cell is called zygote.
• Fertilization takes place in the oviduct or fallopian tube.
• The zygote which is diploid travels down the fallopian tube. As it moves it undergoes several mitotic divisions
forming the embryonic stage called blastocyst.
• Blastocyst moves towards the wall of the uterus and finally gets attached and embedded in the wall of the uterus. This is called implantation.

• The growing embryo forms two membranes chorion and Amnion.
• Chorion establishes connection with the walls of the uterus and helps in the supply of nutrients to the embryo and removal of wastes from the embryo.
• Amnion forms a sac like structure around the embryo. The space between the amnion and embryo is filled with a fluid called amniotic fluid.
• Amnion and amniotic fluid give protection to the embryo against minor mechanical injury.
• Placenta is a tissue formed by the cells from the embryo and the mother. It is formed around 12 weeks of pregnancy.
• Placenta nourishes the growing embryo.
• A tough cord called umbilical cord is also formed by the embryo which is connected to the walls of the uterus through the placenta.
• From 3 months of pregnancy, the embryo is called foetus.

• Pregnancy lasts on an average 9 months or 280 days. This period is called gestation period.
• After this time foetus is expelled from the uterus by the mother – this is child birth.
• This process is complicated and involves the participation of foetus and mother.

Question 14.
What is the significance of cell division in human beings ?
Answer:

• The process of cell division is same in unicellular organisms to highly evolved multicellular organisms like human beings.
• Cell division is the process that transforms a human fertilized egg into a baby in nine months and into an adult in the next 20 years.
• Cell division and function in a multicellular organism is highly regulated. It occurs only when there is a need for it.
• Cells in some organs, such as heart and brain of an individual never divide.
• On the other hand bone marrow cells actively divide to produce red blood cells, which have a short life span (120 days. in the body.
• For example, if you cut your finger and bleed, soon a blood clot forms to stop the bleeding.
• This brings in various chemicals to the site that stimulate skin cells to divide and heal the wound.
• Cell division ceases or stops as the wound is completely healed.
• In contrast, cancer cells do not respond to such growth regulating factors and continuously divide at the expense of normal cells. Thus ultimately killing the host.
• So it becomes important to understand the processes involved in cell division.

Question 15.
Illustrate the process of regeneration in planaria with the help of suitable diagram.
Answer:

• Planaria can be cut into many number of pieces and each piece grows into a complete planaria.
• This development of pieces of an organism into an individual is known as regeneration.
• Regeneration is carried out by specialised cells.
• These cells proliferate and form large number of cells.
• In this mass of cells differentiation occurs to form various types of cells and tissues.
• These changes take place in an organised sequence referred to as development.
• This results in formation of an individual planaria.

II. Asking Questions And Making Hypothesis

Question 1.
What are the consequences if meiosis not happens in the body cells of the organism ?
Answer:

• Each organism has a fixed number of chromosomes.
• This number has to be maintained in its offspring.
• Any sudden change in the number of chromosomes will be harmful to the off-spring. Assume parent has 10 chromosomes.
• In the absence of meiosis during sexual reproduction gametes will also have the same number of chromosomes as parent i.e., 10 chromosomes.
• Union of female and male gametes occur forming zygote during sexual reproduction. The zygote will have the double number of chromosomes as compared with the parent organism, i.e. the number of chromosomes in zygote will have 10 + 10 chromosomes.
• In the next generation, the offspring will have forty chromosomes. If this continues cells in the offsprings will have thousands of chromosomes within few generation.
• This results in formation of abnormalities in each generation. Hence by way of meiotic division, the chromosome number is maintained constant from generation to generation.

Question 2.
What happens in flowering plant if single fertilization only takes place ?
Answer:

• If single fertilization takes place in flowering plants it forms zygote  (pollen tube nucleus + eggs) or Endosperm (pollen tube nucleus + fusion nucleus) only.
• After many changes zygote divides several times to form an embryo within ovule.
• Another part of flower (ovary) grow to form fruit. With single fertilization only fruit (or) embryo with in ovule will form.

Question 3.
What happens if the fallopian tubes are partially blocked and the ovulated eggs are prevented from reaching the uterus
Answer:
Fertilization may take place but the zygote may develop in the tube instead of uterus.

Question 4.
What will happen if there is no mitosis at all in living organisms ?
Answer:

• If mitosis is not present, growth and development of organism will not take place.
• Wound healing does not take place.

Question 5.
Ravi’s father wants to cultivate potato in his field. He wants to clarify some doubts with the agricultural officer. Prepare a list of doubts in form of questions for him.
Answer:

• Which type of soil is suited for growing potato ?
• What are used as seeds for sowing potato crop ?
• What are climatic conditions required for potato crop ?
• What are the vegetative propagation methods to grow potato crop ?
• What are the best ways to prevent early and late blight disease ?
• How are weeds controlled in potato crop ?
• What are the fertilizers required for potato crop ?

III. Experimentation And Field Investigation

Question 1.
What procedure do you adopt to see pollen grain with pollen tube ?
Answer:
Aim : To observe the pollen tube.
Apparatus : Microscope, Sugar solution, flowers (Alium cepa) slide, coverslip, brush.
Procedure :

• Collect any mature flower keep them in sugar solution for 6-7 hours. It enhances the germination of pollen grain.
• Take a slide, put a drop of water on it.
•  With the help of brush tap on flower to collect pollen from flowers already kept in sugar solution.
• Observe under microscope. Draw what you have seen in your notebook.

Question 2.
Sameer wants to observe Rhizopus under microscope. For this
i. What are preparatory activities he has to do ?
ii. What procedure does he follow ? And
iii. What precautions should he take ?
Answer:
i. To observe Rhizopus he has to do the following preparatory activities :

• He has to grow Rhizopus or common mould on his own in a controlled environment.
• Take a bread slice, leave in open air for about an hour, place the bread in plastic bag.
• Sprinkle water over it to have dampness then seal the bag, leaving some air inside, place it in a dark warm place.
• After 2-3 days, you will find black patches (or) thread like growth with masses of black, grey and green fine dotted structures on it.

ii. Materials required: Mould sample, plain glass slide, coverslip, water, disposable gloves, microscope, tooth pick.

Procedure:

• Place a drop of water in the centre of the slide.
• Using a toothpick, scrape very little of the mould and place it on the drop of water.
• Take the cover slip and set it at an angle to the slide, so that one edge of it, touches the water drop, then carefully lower it over the drop so that the cover slip covers the specimen without trapping air bubbles underneath.
• Use the corner of a tissue paper or blotting paper to blot up any excess water at the edges of the cover slip.
• View the slide with a compound microscope first observe under low power.

Observation:

• The common bread mould consists of fine thread like projections called hyphae and thin stems having knob like structures called Sporangia.
• Each sporangium contains hundreds of minute spores.
• When the sporangium bursts, the tiny spores are dispersed in air.

Precautions:

• Keep away from mould who is suffering from allergies and asthma.
• Do not touch mould with bear hands. If you touch it be sure to thoroughly wash your hands afterwards.

Question 3.
How will you stain a microscopic slide showing mitosis in on ion roots?
Answer:
Place the cut tip on a clean microscopic slide. Add 2-3 drops of acetocarmine stain to the slide. Observe it under a compound microscope.

IV. Information Skills And Projects

Question 1.
Observe the following mitotic cell division diagram and answer the questions given below

i. How much time does G1 phase require?
Answer: G1 phase requires approximately 10.50 hours.

ii. What is ‘S’phase?
Answer: ‘S’ phase period of DNA synthesis (synthesis phase)

iii. What is G2 phase ? What changes occur during this phase?
Answer: G2 phase is the time between the end of DNA replication and the beginning of mitosis.
Cell organelles divide and prepare chromosome for mitosis.

iv. What is ‘M’ phase ? How much time does it require?
Answer: ‘M’ phase is cell division phase. It requires 1 hour to complete.

v. How much time is required to complete mitotic cell cycles?
Answer: Approximately 25.30 hours.

V. Communication Through Drawing, Model Making

Question 1.
Draw the life history of flowering plant in the form of block diagram.
Answer:
Life history of a flowering plant:

Question 2.
Label the parts for given diagram and write functions of labelled parts 1, 2, 6 and 7.
Answer:

• Stigma
• Anther
• Petals
• Stamen
• Style
• Sepals
• Ovary

Functions of Stigma, Anther, Sepals and Ovary:
1. Stigma: It receives pollen grains.
2. Anther: Produce pollen grains.
6. Sepals: Give protection to inner whorls.
7. Ovary: It forms ovules and later seeds.

Question 3.
Draw labelled diagram of Human male reproductory system. What is the function of epididymis?
Answer:

The function of epididymis: It stores sperms temporarily.

Question 4.
A person was injured, after several days his wound was completely healed. What type of process took place at the injured part ? Represent these stages with diagram.
Answer:
At injured place wound was healed through mitosis. The stages of mitosis are as follows.

Question 5.
Identify the given picture. What is the message given by it?
Answer:
The given picture is ‘Red ribbon’. The Red Ribbon / Red ribbon clubs gives awareness about HIV / AIDS.

VI. Application To Daily Life, Concern To Biodiversity

Question 1.
Write what programmes you are conducting to provide awareness of a health cleanliness and family planning.
Answer:

• Organising Health camps on World Health day to people of the village.
• Conducting immunisation programs for every three months.
• Supplying tablets on the deworming day.
• Organising seminars by expert doctors on individual health and cleanliness programs.
• Propagating small family norms conducting camps for family planning operations.
• Educating the masses through pamplets on the needs of taking balanced diet.
• Need of using toilets and washing hands and legs before and after meals.
• Educating the people by conducting adult education centres. This is basically required for enlightening the people on health aspects.

Question 2.
Describe what life skills one should develop in Adolescent stage.
Answer:
In order to face challenges of life especially in the context of adolescent stage.

• Decision making skills : This means critical thinking and making right decisions in life.
• Inter personal skills: It means healthy relationship between friends and classmates.
• Communication skills: It means freely expressing their views, fears, doubts, anxiety etc.
• Coping skills: It means to adjust with situations of life.
• Handling peer pressure : It means making value judgements on request from friends.
• Building caring relationships: It means respecting friends and others, especially of the opposite gender.

Question 3.
Write some slogans against female foeticide.
Answer:

• Stop female foeticide – Save girl child.
• Don’t kill our mother, wife, daughter – Because all are girls.
• ‘Your daughter may be tomorrow’s a Doctor, an Engineer, a Scientist or a Teacher save them.”

## TS 10th Class Biology Important Questions 5th Lesson Coordination

These TS 10th Class Biology Chapter Wise Important Questions 5th Lesson Coordination will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 5th Lesson Coordination

1 Mark Questions:

Question 1.
A plant which grows near a window bends towards Sunlight. Write the reason for it.
Answer:
Auxins are the plant hormone responsible for the growing of the stem towards light. Auxins are synthesized at the tip of the stem. Bending of the plant towards light is called phototropism by the action of auxine to show response towards the sunlight.

Question 2.
Write the name of the nerve given in the following diagram and write its function.
Answer:
The given diagram is the Sensory Neuron. They are also called Afferent nerves.
Function : They carry messages towards central nervous system (Brain or spinal cord) from nerve endings on the muscles of different sense organs. They detect ‘stimuli’ or the change in surroundings.

Question 3.
Identify the given part in the diagram and write its use.
Answer:

• Synapse.
• k is a functional region of contact between two neurons where information from one neuron is transmitted to another neuron.

Question 4.
Name the part of the brain that maintains the equilibrium.
Answer:
The part of the brain that maintains the equilibrium is cerebellum.

Question 5.
You may eat grapes with no seeds. How they are formed? Write some other fruits names.
Answer:
Grapes without seeds are produced by an asexual method called parthenogenesis. Watermelon, pomegranate.

Question 6.
How many types of nerves are there ? What are they?
Answer:
On the basis of pathways followed, nerves are classified mainly into three types.

• Afferent Neurons
• Efferent Neurons
• Association Neurons.

Question 7.
What are Afferent neurons?
Answer:
Nerves which carry messages towards the central nervous system (spinal cord or brain) from nerve endings on the muscles of different sense organs that sense the change in surroundings are called Afferent nerves. These are also called ‘sensory’ nerves.

Question 8.
What are Efferent neurons?
Answer:
The nerves which carry messages from the central nervous system to parts that shall carry out the response or the effectors (muscles) are called efferent neurons. They are also called ‘motor’ nerves.

Question 9.
What are association nerves?
Answer:
These nerves which link together the afferent and efferent nerves are called association nerves.

Question 10.
What are reflexes?
Answer:
The responses which we may not have a control are called reflexes.

Question 11.
What is a Reflex arc?
Answer:
Picking up information of a stimulus to generate a response involves a pathway from detectors to brain or spinal cord or a set of nerve cell heads near spinal cord to the effectors. Such a single pathway going up to the spinal cord from detectors and returning to effectors is a reflex arc.

Question 12.
What are unconditioned reflexes?
Answer:
There are some responses which are inborn and inherited from the parents. These are called unconditioned reflexes.
Ex: Withdrawing the hand when you touch fire.

Question 13.
What are conditioned reflexes?
Answer:
Conditioned reflexes are not inherited. These reflexes develop in an organism by repeated exposure to the similar stimuli.
Ex: Standing in attention, when you hear National Anthem.

Question 14.
What are the components of central nervous system?
Answer:
Central nervous system includes brain and spinal cord.

Question 15.
What are the divisions of brain ?
Answer:
The divisions of brain are:

• Fore brain – cerebrum, diencephalon
• Mid brain – optic lobes
• Hind brain – cerebellum, medulla oblongata.

Question 16.
What is enteric nervous system?
Answer:
There is a system of neurons present in our digestive tract that can function even independently of either central nervous system or peripheral nervous system. It has been nick named as a small brain and the system is called as ENTERIC nervous system.

Question 17.
What is sympathetic nervous system?
Answer:
The sympathetic nervous system is formed by the chain of ganglia on either sides of the vertebral column and the associated nerves.

Question 18.
What is parasympathetic nervous system?
Answer:
The parasympathetic nervous system is formed by the nerves arising from the ganglia of the brain and the posterior part of the spinal cord.

Question 19.
Do plants also have control system?
Answer:
To control and coordinate the functions in plants also produce some chemical substances which are called hormones.
They are auxins, gibberellins, cytokinins, ethylene and abscisic acid.

Question 20.
What are voluntary actions ? Give examples.
Answer:
The movements under the control of the conscious mind (voluntary) are called voluntary actions.
Example: Kicking football, lifting bucket of water, lifting books, running, walking, playing, eating, etc., which are done with our knowledge.

Question 21.
What are involuntary actions ? Give examples.
Answer:
The movements which are not under the control of the conscious mind are called involuntary actions.
Example: Respiration, circulation, digestion, heart beating.

Question 22.
How do reflexes take place in our body?
Answer:
Reflexes are fast, immediate, automatic and involuntary responses of the body. They occur without our thinking. Brain is not involved in these actions.

Question 23.
How many types of actions are controlled by nervous system in our body?
Answer:
Two types of actions were controlled by nervous system. They are voluntary and involuntary actions.

Question 24.
How many types of reflexes are present?
Answer:
There are two types of reflexes.

• Unconditional reflexes
• Conditional reflexes.

Question 25.
What is the reaction of the body when we step on a sharp edged object?
Answer:
Our leg muscle responds immediately and raises up the leg, when we step over a sharp edged object.

Question 26.
Why is a system of control and coordination essential in living organisms?
Answer:

• Increase the chances of survival by responding to stimuli.
• Different body parts function as a single unit.
• To maintain a homeostasis.

Question 27.
What will happen when plant is exposed to unidirectional light?
Answer:
Stem bends towards unidirectional flow of light. It is called phototropism.

Question 28.
A part of the hind brain makes possible activities like walking, skating, riding a bicycle and picking up a pencil. Name this part of the hind brain.
Answer:
Cerebellum.

Question 29.
Name the plant hormone which inhibits growth and causes wilting of leaves.
Answer:
Abscisic acid.

Question 30.
Taking the example of heart beat, justify the antagonistic (opposite) action of the sympathetic and parasympathetic nerves.
Answer:
Sympathetic system increases contraction and rhythm and parasympathetic system decreases contraction and rhythm with respect to heart beat.

Question 31.
Name the part of neuron where information is acquired.
Answer:
Dendrite.

Question 32.
Who transmits nerve impulse across the synapse?
Answer:
Neurotransmitters.

Question 33.
Why do leaves drop off seasonally?
Answer:
The leaves drop off seasonally as they stop producing auxins which normally prevent the formation of abscission zone that cuts off nutrients and water supply to leaves.

Question 34.
Have you ever observed the duration of anger?
Answer:
The duration of anger will be sometimes ten minutes or fifteen minutes or according to the situation.

Question 35.
What may happen if anger persists for a longer period?
Answer:
If anger persists for longer time, regular metabolic activities are disturbed.

2 Mark Questions:

Question 1.
Draw the diagram of nerve cell and label it.
Answer:

Question 2.
What is the significance of the adrenal gland in the human body?
Answer:
Adrenal gland secrets adrenalin. it helps in

• Increase heart beat rate
• Rise in blood sugar
• Dilation of the coronary artery
• Dilation of pupil of the eye.

Question 3.
Write the difference between hormone and enzyme.
Answer:

 Hormone Enzyme 1 These are secreted by ductless glands. 1. These are secreted by duct glands. 2. These are travel through blood. 2. These are travel through the ducts. 3. Less in quantity. 3. More in quantity. 4. Reaction is slow. 4. Reaction is fast. 5. Involved in metabolic activities 5. Involve in digestion. 6. Ex: Insulin 6. Ex: Lypase

Question 4.
What questions you will ask a neurologist on function of brain?
Answer:

• How does alcohol cosumption affect the brain?
• Which part of brain is responsible for creatMty?
• How do we get fits?
• How do we get paralysis?
• What kind of food should we take to increase I.Q.?

Question 5.
Label a, b, c, d in the diagram given below and write their functions.
Answer:

a. Sensory Neuron/Afferent Neuron: These carry messages towards the central nervous system.
b. Motor Neuron/Efferent Neuron : These carry messages from central nervous system to body parts.
c. White Matter
d. Effector Muscles: Respond to stimuli.

Question 6.
Observe the following table and answer the questions.

 Hormones Uses Thyroxine Normal growth rate, effect on metabolism Auxins Cell elongation and differentiation of shoots and roots

i. Name the phytohormone in the table.
ii. Name the hormone which Influences growth rate in humans.
Answer:
i. Auxin
ii. Thyroxine.

Question 7.
Explain two tropic movements with suitable examples.
Answer:

• Phototropism: Response of plant to light cite example is called phototropism.
Ex: sunflower
• Geotroplsm : Response of a plant to gravitational force Ex: root growth of plant
• Hydrotropism: Response of root to water availability in the soil.
Ex: Plants which are growing very close to rocks and walls.
• Thlgmotropism: Response to make contact or touch is called Thigmotropism.
• Chemotroplsm : Response to chemical is called chemotropism (Stigma secretes sugary substances)

Question 8.
Prepare a table showing tropic movements in plants in response to stimuli.
Answer:

 SI. No. Tropic movement Response to stimuli 1. Phototropism Movement towards light. 2. Geotropism Respond positively for gravitational force. 3. Hydrotropism Roots grow towards presence of water in the soil. 4. Thigmotropism Tendrils and climbing plants grow towards support.

Question 9.
Write two voluntary functions and two involuntary functions you have observed in your body.
Answer:
a. Examples for voluntary functions:

• Cleaning the table
• Playing on the keyboard.

b. Examples for involuntary functions:

• Salivating when food is kept in the mouth
• Closing of eyes when bright light is focussed.

Question 10.
Plants shows tropic movements in different situations. Give examples.
Answer:
1. Movement of individual parts of plants is possible when they are subjected to external stimuli. This type of response is called tropism or tropic movement.

2. The response of a plant to light is called phototropism. Respond of plants for gravity is called geotropism. Movement of plant towards water is called hydrotropism. The type of response by plants to make contact or touch is called thigmotropism. The response of plants to chemicals is called chemotropism.

Question 11.
Divide the following into groups. Walking, blinking of eyelids, heart beat, laughing, digestion of food and reading. How do you divide them into groups?
Answer:
These can be divided into voluntary actions, involuntary actions and reflex actions.

• Voluntary actions : Walking, laughing, reading
• Involuntary actions : Digestion of food, heart beat
• Reflex actions : Blinking of eye lids

Question 12.
What are the differences between unconditioned and conditioned reflexes?
Answer:

 Unconditioned reflexes Conditioned reflexes 1. They are inborn reflexes. 1. They are not inherited. These are learned by doing the same at several times. 2. They are inherited shown from the birth. 2. These have to be learned by the organism. 3. These are present in all individuals and are basically same. 3. They are not same in all individuals. 4. Ex: With drawing the hand when you touch fire. 4. Ex: Standing in attention when you hear National Anthem.

Question 13.
Write the components of reflex arc and their functions.
Answer:

• The structural and functional unit that carries out reflex action is called a reflex arc.
• It consists of five components.
• They are receptor, a sensory nerve, a association neuron, a motor nerve and an effector organ.
 SI. No. Component of reflex arc Functions 1. Receptor Receives information and generates impulses. 2. Sensory neuron (Afferent) Carries information from the receptor to the interneurons in the spinal cord. 3. Interneuron (Association neuron) Processes the information and generates responses. 4. Motor neuron (Efferent) Carries the information from the spinal cord to the effector organ. 5. Effector organ Receives the information from the effer­ent neuron and shows the appropriate responses.

Question 14.
How is brain in the human beings protected from injuries?
Answer:

• Brain is a very soft tissue and is surrounded by a bony case called cranium, which is made up of skull bones.
• Cranium protects the brain from injuries.
• Brain is covered by three membranes – Dura matter, Archnoid membrane and pia matter. They give protection to the brain.
• The cerebro – spinal fluid which flows between the outer and middle membranes, protect the brain from injuries and also the cerebro-spinal fluid provides nutrients to the brain and spinal cord.

Question 15.
What are plant growth substances ? Give examples.
Answer:

• Plant growth substances are the chemical (organic) substances which are produced in plants and act at minute concentration on growth and other phisiological functions of plants.
• There are five major types of plant growth substances. They are auxins, gibberellins, cytokinins, ethylene and abscisic acid.

Question 16.
What are the functions of cytokinins?
Answer:

• Cytokinins are capable of stimulating cell division along with auxins.
• They promote cell elongation.
• They have ability to delay the process of ageing in leaves.
• Cytokinins can prolong the life of fresh-leaf crops like cabbage, spinach.
• They are also used for keeping the flowers fresh.
• Cytokinins are most effective in breaking dormancy of buds and seeds.
• The levels of cytokinins decrease in senescing leaves.

Question 17.
What is ABA Explain its function in the plant.
Answer:

• ABA means Abscisic acid. It is the plant growth inhibiting substance.
• It Induces dormancy in buds, tubers and many seeds.
• ABA is responsible for the formation of separation layer or abscission layer between main plant and the leaf or between plant and flower or fruit. It results in the falling of leaves, fruits and flowers.
• It prevents the water loss during drought conditions by closing the stomata.

Question 18.
What is ethylene ? Explain its action.
Answer:

• Ethylene is a gaseous growth inhibiting substance.
• Ethylene causes ripening of the fruits.
• It modifies the growth of the plant by inhibiting stem elongation.
•  It accelerates abscission of leaves, flowers and fruits.

Question 19.
How do living organisms respond to the changes in the environment?
Answer:

• All living organisms have a mechanism to identify the changes in the environment and respond to the changes.
• There are specific cells in the organisms which have ability to respond to the environmental changes.

Question 20.
Why are samepaileirs of diabetes treated by giving injections of insulin?
Answer:

• Diabetes is a condition in which sugar level in blood is very high.
• Insulin hormone is released by pancreas glands which regulate the blood sugar level.
• In diabetic patients pancreas is stopped releasing insulin hormone.
• In it is not secreted in proper amounts, the sugar level in the blood rises, causing many harmful effects.
• Due to this reason diabetic patients are treated by giving injections of insulin.

Question 21.
On touching a hot plate you suddenly withdraw your hand. Which category of neurons become active first and which are next?
Answer:

• On touching a hot plate, first the sensory organs are activated which take the information to the brain or the spinal card.
• Next the motor neurons become active and bring the impulses from the brain to the muscles.
•  In receiving these impulses, the muscles contract and the hand is immediately removed from the hot plate.

Question 22.
How does the plant shoot bend, when the plant is placed in a room having only one open window?
Answer:

• When the plant is placed in such a room that has only one open window, the shoot of the plant bends towards the direction of light.
• Plant hormone auxin is formed that diffuses towards the shady side of the shoot and stimulates the cells to live longer on the side of the shoot which is away from light.
• In this way the shoot bends towards the light.

Question 23.
Give a reason to explain why adrenaline helps in dealing emergency situations.
Answer:

• Adrenaline increases the heart beat and breathing rate which results in the supply of more oxygen to muscles.
• It reduces the blood to the digestive system and skin as a result the blood is further diverted to skeletal muscles.
• All these responses together prepare the body to leal with the emergency situations.

Question 24.
Rami, has met with an accident. After that he has lost the capacity to
i. walk in straight line
ii. smell anything
iii. does not feel full eating.
Which part of brain is damaged in each case?
Answer:
i. Cerebellum is hurt which affects walking in straight line.
ii. Smelling part of fore brain is injured.
iii. The sensation of feeling full eating is because of a centre associated with hunger, which is in a separate part of the fore brain. The sensation of feeling full is not because of injury to this centre present in fore brain.

Question 25.
What is the difference between a reflex action and walking?
Answer:

 Reflex action Walking 1. It is a spontaneous immediate response to a stimulus. It happens without thinking. 1. It is a response to the information transmitted by nerves to muscles of the legs. In this case thinking is involved. 2. Keflex action is controlled and coordinated by spinal cord. 2. Hind brain instructs and controls leg muscles to move. 3. It is an involuntary action. 3. It is a voluntary action.

Question 26.
How do you feel when you realize that plants respond to the stimuli of their surroundings ?
Answer:

• It is very interesting and amazing to observe trophic and nastic movements of plants in our surroundings.
• For example, the bending of shoots of creepers towards light kept near the window.
• The plant roots always grow downwards.
• The creepers like cucumber and bitter gourds develop tendrils in response to contact or touch.
• Butterflies fluttering around the flowers for nectar.

Question 27.
Why is anger short living factor ?
Answer:
Anger is always short lived factor. Increased levels of adrenalin are responsible for anger. When the levels of adrenalin in the blood come down slowly. The anger also comes down. We came to normal state.

Question 28.
What will happen if it is continued for longer periods of time ?
Answer:
The sugar levels in the blood rise than normal level. Blood pressure increases, burning sensation in the heart, stomach upsets are the some of the abnormal conditions may happen.

4 Mark Questions:

Question 1.
Analyze the information given below. Write answers to the questions given below.

 Hormones Uses Auxins Cell elongation, differentiation of shoots and roots. Cytokinins Promote cell division, delaying the ageing in leaves, opening of stomata. Gibberellins Germination of seeds, sprouting of buds; elongation of stem; stimulation of flowering; development of seedless fruits, breaking the dormancy in seeds and buds. Abscisic acid Closing of stomata; seed dormancy, promoting ageing of leaves. Ethylene Ripening of fruit.

i. What are Phytohormones ? Write the names of two phytohormones.
Answer:
Phytohormones: The hormones present in the plants are called phytohormones.
Names of phytohormones: Auxins, Cytokinins, Gibberellins, Abscisic acid, Ethylene

ii. Which hormone is responsible for closing of stomata and which hormone acts against it ?
Answer:

• Abscisic acid is responsible for closing of stomata.
• Cytokinin acts against it.

iii. What are the functions performed by abscisic acid ?
Answer:
Functions of abscisic acid :

• Closing of stomata
• Seed dormancy
• Promotes the ageing of leaves.

iv) Which hormones help in the growth ?
Answer:
Auxins, Gibberllins and cytokinins help in the growth.

Question 2.
Observe the following information and answer the following questions.

 S.No. Hormones Uses 1. Auxins Cell elongation and differentiation of shoots and roots. 2. Abscisic acid Closing of stomata, seed dormancy 3. Ethylene Ripening of fruit 4. Cytokinins Promote cell division, promote sprouting of lateral buds, delay ageing of fruits.

i. What do we call the hormones that are present in plants?
Answer:
We call phyto hormones which are present in plants.

ii. Name the hormones which are helpful In the growth of the plants.
Answer:
Auxins, gibberellins, cytokinins are helpful in the growth of the plants.

iii. Farmers keep carbide powder in between raw mangoes. What might be the reason? What will be the end result after 3 to 4 days?
Answer:
Carbide release Ethylene, which promotes the fruit ripening. After 3 or 4 days fruits will ripen.

iv. Plants also respond like animals. Do you agree with this statement ? Support your answer.
Answer:
Yes, plants also respond like animals. They shut off leaves in summer, germinate in  rainy season, blooms according to seasons.

Question 3.
What are the divisions In the brain? What are their functions?
OR
Explain the different parts of the brain and their functions in a table form.
OR
Write in a tabular form the different parts of human brain and their functions.
Answer:
1. Brain has the following divisions.

• Fore brain – Cerebrum, diencephalon
• Mid brain – Optic lobes
• Hind brain – Cerebellum, medulla.

2. Functions of the various parts of the brain.

 Parts of the brain Functions Cerebrum i. Seat of mental abilities, controls thinking memory, reasoning, perception, emotions and speech. ii. Interprets sensations and responds to cold, heat, pain and pressure. Diencephalon i. Relay centre for sensory impulses, such as pain, temperature and light. ii. Reflex centre for muscular activities. iii. Centre for certain emotions such as anger. iv. Centre for water balance, blood pressure, body temperature, sleep and hunger. v. The hypothalamus controls the pituitary gland, which functions as the master gland Mid brain i. It relays motor impulses from the cerebral cortex to the spinal cord and relays sensory impulses from the spinal cord to thalamus, reflexes for right and hearing. Cerebellum i. Maintains posture, equilibrium and muscle tone. ii. Coordinates voluntary movements initiated by cerebrum. Medulla oblongata i. Contains centre for cardiac, respiratory and vasomotor activities. ii. Coordinate reflexes like swallowing, coughing, sneezing and vomiting.

Question 4.
Read the following table and answer the questions given below.
Answer:

 S.No. Name of the gland Location Hormone secreted Response of the body to hormone 1. Pituitary Floor of brain Somatotropin Growth of bone. Gonadotropin Activity of ovary and testis. 2. Thyroid Neck Thyroxine General growth rate and metabolic activity. 3. Ovary Lower abdomen Estrogen Growth of the uterus and skeleton of the pelvis. 4. Testis Scrotal sac Testosterone Growth of male secondary sexual characters.

1. Write the importance of glands and hormones.
Answer:
Glands and hormones controls and coordinates various functions of the body with nervous system.

2. Which hormone Is responsible for growth of bone?
Answer:
Somatotropin is responsible for growth of bone.

3. What happens if testosterone is not secreted?
Answer:
Secondary sexual characters are not developed if testosterone is absent.

4. Where is the gland that secretes thyroxine located?
Answer:
Thyroid gland which secretes thyroxine is located near the neck.

5. Which glands are common in male and female?
Answer:
Pituitary, thyroid, adrenal glands are common in male and female.

Question 5.
Explain the different types of adaptations in plants with suitable examples.
Answer:

• Most plants can aerate their roots by taking in the oxygen through the lenticels or through the surface of their root hairs
• But plants which have their roots in very wet places, such as ponds or marshes, are unable to obtain oxygen.
• They are adapted to these water-logged conditions by having much larger air places which connect the stems with the roots, making diffusion from the upper parts much more efficient.
• The most usual adaptation is to have a hollow stem.
• The problem of air transport is more difficult for trees.
• An exception is the mangrove tree of the tropics which have aerial roots above the soil surface and takes in oxygen through these roots.

Question 6.
Which system of our body is called second brain ? Why?
Answer:
1. Enteric nervous system is called “second brain”.

2. The neural apparatus of our digestive tract comprises of such a vast and complicated network of neurons.

3. Nervous system of gut is not only constricted to digestion or inflict the occasional nervous pang of hunger, but also mass of neural tissue is filled with important neurotransmitters.

4. Enteric nervous system is connected with big brain in our skull.

5. It determines our mental state and plays key role in certain diseases throughout the body.

6. The digestive tract is exposed to a large variety of psychochemical stimuli from the external working in the form of ingested food.

7. The intestine act as a rich store of coordinated moments of its muscular apparatus along with the neural apparatus.

8. Enteric nervous system consists of sheaths of neurons in the walls of our gut, which measures about 9 meters from the oesophagus to Anus. So it is called enhene nervous system.

9. Second brain involves in stimulating and coordinating breaking down of food, absorbing nutrients, and expelling of waste requires chemical processing, mechanical mixing and rhythmic muscle contractions.

10. It equipped with its own reflexes and senses, the second brain can control several gut functions often independently of the brain.

Question 7.
Karthik is suffering from excess sugar in urine and Varun is suffering from repeated dilute urination. What are the reasons for these diseases? Explain.
Answer:

• Excess sugar in urine condition is known as diabetes milletus. (sugar diabetes)
• Repeated dilute urination is known as diabetes insipidus. (diuretic condition)
• Deficiency of insulin causes high level sugar in the blood and urine. It leads to diabetes milletus. (Sugar diabetes)
• Vasopress in maintains osmotic concentration of body fluids.Deficiency of vasopress in causes excessive repeated dlilute urination it is called as diabetes insipidus.

Question 8.
Analyse the following information and answer the questions.

 SI. No. Organ List-1 Effect of Nervous system List-2 Effect of Nervous system 1. Eye Dialates pupil Constricts pupil. 2. Mouth Inhibits salivation Stimulates salivation 3. Lungs Relaxes bronchi Constrict bronchi. 4. Heart Accelerates heart beat Heart beat to normally. 5. Blood vessels Increase blood pressure Decrease blood pressure. 6. Pancreas Inhibits Pancreas activity Stimulates Pancreas activity.

i. Write two functions of Sympathetic Nervous System.
ii. Name two organs that are Influenced by Parasympathetic Nervous System.
iii. Name the Nervous system mentioned in the table that Increases the blood pressure.
iv. What systems constitute Autonomous Nervous System?
Answer:
i. Dilates pupil, inhibits salivation, relaxes bronchi, accelerates heart beat, etc.
ii. Eye, heart, pancreas, etc.
iii. Sympathetic nervous system
iv. Sympathetic and para sympathetic nervous system.

Question 9.
Explain the Phytohormones which controls growth in plants.
Answer:
Major plant hormones and their action :

 Hormones Uses Auxins Cell elongation and differentiation of shoots and roots. Cytokinins Promote cell division, promotion of sprouting of lateral buds, delaying the ageing in leaves, opening of stomata. Gibberellins Germination of seeds and sprouting of buds; elongation of stems; stimulation of flowering; development of seedless fruits, breaking the dormancy in seeds and buds. Abscisic acid Closing of stomata; seed dormancy, promoting aging of leaves. Ethylene Ripening of fruit.

Question 10.
Analyse the table and answer the following questions.

 Sl.No. Part of Brain Functions 1. Cerebrum Mental abilities, memory, speech. 2. Diencephalon Sensory impulses, emotional impulses, muscular activities. 3. Midbrain Reflexes of sight and hearing. 4. Cerebellum Equilibrium. 5. Medulla oblongata Respiratory, cardiac centres, blood pressure.

i. Which part of the brain recollects the childhood incidents?
Answer:
Cerebrum.

ii. Write two parts of hind brain.
Answer:
Cerebellum, med ulla oblongata.

iii. Name the part of the brain that will not function in drunken person.
Answer:
Cerebellum.

iv. Name the part of the brain that controls involuntary actions.
Answer:
Medulla oblongata.

Question 11.
Write contrasts and comparisons of the style of response in plants and animals to the stimuli.
Answer:

• Both plants and animals react to various stimuli around them. But the method of responding to stimuli is not similar in plants and animals.
• Higher animals respond to stimuli because they have a nervous system and an endocrine system.
• Plant do not have a well defined nervous or endocrine system. They do have some mechanism of control by means of some chemicals or hormones.
• Plants can sense the presence of stimuli like light, heat, water, touch, pressure, chemicals, gravity, etc.
• The hormones present in the plants called phytohormones control response towards the stimuli. Phytohormones coordinate the activities of the plant usually by controlling one or the other aspect of the growth of the plant.

Question 12.
Read the below paragraph and write answers.
There is systematic method in showing response to stimuli. There is different stages in it. First stage starts with the response recognising the changes in out-side or inside of the body atmosphere with recognising the stimuli. Transmitting the received information is second stage, analysing that information is third stage and showing correct response to that stimuli is the last stage.

a. What does this information show ?
b. Convert the above information into flow chart.
c. Write about the mechanism that conducts this action.
A.
a. It shows the systematic method in showing response to stimuli.

b.

c. Nervous system can sense the changes inside and outside the body through specialised cells called Receptors. This information in the form of small electrical currents is analysed and responses are generated in the nervous system. These responses once again in the form of small electrical currents are conveyed to the appropriate organs such as muscles and glands at a greater speed. Nervous system may store this information for future use.

Question 13.
See the below action. What does it indicate ? Explain with an example.

Answer:
It indicates the stimulus – response action. This stimulus response can be explained with an example. Suppose a mosquito is biting you on your arm. Mosquito bite is stimulus. The receptor in the skin responds and send the information in the form of electrical impulses through sensory nerve to spinal cord or brain.

Brain or spinal cord analyses the information that the mosquito bite is causing pains. The brain or spinal cord sends the message through motor nerve to the effector organ i.e. hand to kill the mosquito. As per the message our hand immediately hits the mosquito and kills it.

Question 14.
Describe the structure of brain.
OR
All the activities of human are controlled by a vital organ. With the help of a neat labelled diagram describe its structure.
Answer:

• When compare to body weight human brain quite large as compared to several other animals.
• The brain is present in the hard bony box like structure called cranium.
• It is covered by three layers called the meninges. The meninges are continued and coyer the spinal cord as well.
• It serves as a shock – absorbing medium and protects the brain against shocks / jerks along with meninges and cranium.
• The nerve cell bodies together with capillaries form a mass called grey matter while the inyelinated axons form white matter.
• The grey matter is in the outer layers while the white matter is present towards inner layers.

Question 15.
Describe the structure of spinal cord.
Answer:

• Spinal cord extends from the back of the hind brain (medulla oblongata) to the back of the stomach or lumbar region.
• It is cylindrical in shape. It passes through the neural canal of the vertebral column.
• The white matter is towards periphery, while grey matter is towards the centre of the spinal cord.
• In the cross-section, grey matter of the spinal cord is in the form of ‘H’ and it is called ‘horn’.
• In the middle of the grey matter of the spinal cord, there is a canal called spinal canal which is filled with Cerebro-spinal Fluid.
• From the sides of spinal cord 31 pairs of nerves arise and supply branches to various parts of the body.
• Function of spinal cord is receiving and sending information from brain to various parts and from various parts to brain. And it also helps in reflex actions.

Question 16.
What were the studies of the experimentalists on spinal cord?
Answer:

• The role of spinal cord in nervous control was studied largely by the experimentalists of the sixteenth and seventeenth centuries.
• They found that the Greeks concept of the brain was erroneous. Animals have shown to have the ability to respond to stimuli even when the brain was removed.
• The animals still produced muscular movements if it’s skin was pinched or pricked.
• The observers ‘Leonardo Davinci’ and ‘Stephen Hales’ recorded that the animal died as soon as spinal cord was damaged by pushing a needle down it.
• It is suggested that the spinal cord was not simply a trunk road for instructions from the brain but might be a control center in it’s own right.

Question 17.
What do you understand by peripheral nervous system?
Answer:

• The peripheral nervous system consists of nerves that arise from the brain and spinal cord.
• The peripheral nervous system has 43 pairs of nerves of these 12 pairs are called CRANIAL NERVES and the rest of 31 pairs are called SPINAL NERVES.
• The grey matter of the spinal cord appears like butterfly or in the shape of letter ‘H’. Each segment of the ‘H’ shaped grey matter is called ‘HORNS’.
• The upper horns are called ‘DORSAL HORNS’ and the lower horns are called ‘VENTRAL HORNS’
• The sensory fibres originate from the dorsal horn of the spinal cord. They carry information from body organs to spinal cord.
• The motor fibres take their origin from the ventral horns of the spinal cord. These supply information required for the movements of the muscles.

Question 18.
Give an example of autonomous nervous system.
Answer:
Certain involuntary functions (without our knowledge) are controlled by autonomous nervous system takes place in our body. A very evident observation is the reduction and expansion of the pupil of our eye. When we enter a dark room, we cannot see anything immediately. Slowly we are able to see the things around us in the room. This is because of increase in diameter of pupil, which allows more light in.

When we come out of the dark room into broad day light, the diameter of the pupil decreases allowing less light to enter into the eyes. Both these functions are under the influence of the autonomous nervous system.

Question 19.
Give an example of autonomous nervous system.
Answer:
Certain involuntary functions (without our knowledge) are controlled by autonomous nervous system takes place in our body. A very evident observation is the reduction and expansion of the pupil of our eye. When we enter a dark room, we cannot see anything immediately.

Slowly we are able to see the things around us in the room. This is because of increase in diameter of pupil, which allows more light in. When we come out of the dark room into broad day light, the diameter of the pupil decreases allowing less light to enter into the eyes. Both these functions are under the influence of the autonomous nervous system.

Question 20.
Explain how coordination takes place without nerves by the story of Insulin.
Answer:
In 1868 Paul Langerhans, professor of pathology at the university of Freburg in Germany, working on the structure of the pancreas, noted certain patches of cells quite different in appearance from the normal tissue cells of the organ and richly cupplied with blood vessels. They are known islets of Langerhans, but their function remained unknown.

When pancreas is removed from the body of experimental animal, it was found that the animal developed a well-known human ailment ‘sugar diabetes’. It is a cause in man was unknown, but evidence pointed to the pancreas as a possible role.

The animal treated with pancreatic Langerhans would not develop diabetes. This was really a strong evidence that the level of blood sugar is linked with the islet cells. The chemical substance secreted by these cells is the hormone insulin.

We can understand that the coordination also can be brought by the hormones, which are directly liberated into the blood. Insulin is now produced in large quantities for the treatment of human sufferers from sugar diabetes, to whom it is administered by injection into the skin.

Question 21.
What are endocrine glands ? Mention their functions.
Answer:
Endocrine glands : Endocrine glands are the ductless glands. They secret complex organic substances called hormones directly into the blood. Hormones are transported through blood to different tissues. Their secretions act as biochemical messengers in the body.

Functions : The hormones secreted by these glands play an important role in co-ordinating various organ systems. Hormones can increase or decrease the metabolism and synthesis of substances like proteins, carbohydrates and lipids. Irregular functioning of these glands may lead to serious diseases. The quantity of hormone required is very minimum (1/10,00,000 gram). A slight increase or decrease may brings out large changes in the target tissue

Question 22.
What is feedback mechanism ? Explain.
Answer:
1. A feedback mechanism is a loop in which a product controls its own production.
2. The production of several hormones is controlled in this manner.

Example 1.

• A pituitary hormone, ‘prolactin’ stimulates mammary glands to produce milk.
• As the baby sucks, more prolactin is produced enhancing milk production.

Example 2.

• When the glucose level in blood rises above normal level certain cells of pancreas respond by producing more amount of insulin hormone into the blood effectively lowering blood glucose levels.
• Lowering to normal level results in turning down the secretion of the hormone.
• If the glucose level comes back to normal level secretion of insulin is automatically reduced. There are also ways in which hormonal secretion may also enhance the production of product and vice versa.

Question 23.
What is autonomous nervous system ?
Answer:
The system that helps to bring about activities of internal organs is called autonomous nervous system. Example : heart beat, breathing, etc. Autonomous nervous system consists of nerve centres called GANGLIA. From these nerve centres nerves are given off to the various organs like heart, lungs, kidneys, alimentary canal and muscles.

The autonomous nervous system is automatic and involuntary. It controls the involuntary actions of heart, the working of the lungs, movement of muscles in the alimentary canal and others. The autonomous nervous system is divided into parasympathetic nervous system and sympathetic nervous system.

Question 24.
Write differences between nastic and tropic movements.

 S.No. Nastic movements Tropic movements 1. Growth Growth independent movements Growth dependent movements 2. Time of action Immediate Slow 3. Response to stimulus Non-directional Directional 4. Reason for action Change in turgor Cell division 5. Alternate name Nasties Tropism 6. Examples Folding of leaves of touch me – not (mimosa), opening and closing of stomata. Phototropism, geotropism, hydropism, chemotropism.

Question 25.
On the basis of pathways, how many types of nerves are there ?
Answer:
On the basis of pathways followed, nerves are classified mainly into three different types. They are :

1. Afferent Neurons
2. Efferent Neurons
3. Association Nerves.

1. Afferent Neurons: They carry messages towards the central nervous system (brain or spinal cord) from nerve endings on muscles of different sense organs that sense the change in surroundings are called stimulus detectors. These are also called ‘sensory’ nerves.

2. Efferent Neurons : They carry messages from the central nervous system to the parts that shall carry out the responses. They are also called “motor” nerves.

3. Association Nerves : They link together the afferent and efferent nerves.

II. Asking Questions And Making Hypothesis

Question 1.
Can you imagine how it (the tendrils of plants growing towards a support) is happening ? Would you think it is a responding to a stimulus ?
Answer:
Plants also can response to stimulus. They can sense the presence of stimulus like light, heat, water, touch, pressure, chemicals, gravity, etc.
The hormones present in the plants are called phytohormones. These control responses towards the stimuli.

Question 2.
What will happen if intake of iodine in our diet is low ?
OR
Why is the use of iodised salt advised ?
Answer:
1. It is advised to use iodised salt to prevent goitre (enlargement of the thyroid gland).
2. Iodine is required for the proper functioning of thyroid.
3. Iodine stimulates the thyroid gland to produce thyroxin hormone.
4. This hormone regulates carbohydrate, fat and protein metabolism in our body.

Question 3.
What happens if testis and ovary do not function properly ?
Answer:

• If the testis does not work properly Testosterone may not secrete, as a result secondary sexual characters like growth of hair on face, muscular development, deepening of voice, normal sexual behavior and development of male sex organs may not takes place.
• If ovary does not work properly Estrogen and Progesteron may not secrete as a result growth of the uterus and skelton of the pelvis may not take place.
• Menstrual cycle may not take place in female, as a result ovary may not release and children may not occur.

Question 4.
If you get a chance to met a neurologist/neurophysician, what type of questions will you ask to keep your Nervous System healthy ?
Answer:
To keep our nervous system healthy I will ask following questions.

• What kind of diet you will suggest to keep our nervous system healthy ?
• What is meant by brain stroke ?
• How does paralysis occur ?
• What are the reasons for paralysis ?
• Why polio (patients) is not curable ?
•  Why some people do creative works easily, when compared to others ?
• Why cell division does not occur in neurons ?
• What are factors effect the nervous system ?
(You can add your own questions based on concept)

Question 5.
What Will happen if thyroid is removed ?
Answer:

• If thyroid is removed from body, tissue metabolism and growth may stop.
• Absorption of glucose will not takes place, as a result sugar levels will increase and ultimately it leads to health problems.

III. Experimentation And Field Investigation

Question 1.
Write the following items about the experiment you have done to show that plants move to light.
a. Used equipments
b. Method of the experiments
c. Observed results.
Answer:
a. Used equipments : Glass jar filled with soil, bean seed

b. Method of experiment:
Take a glass jar and fill with soil. Sow a bean seed near the wall of the jar. This helps us to observe how root and shoot are growing. After 4-5 days we will notice seed germination. Keep the jar under the sun – observe how root and shoot grows. Then fill the glass jar and keep the plant horizontally. Observe the direction of root and shoot growth for more than a week.

c. Observed results:
The shoot position (tip) of the plant grows towards light. It bends towards light. It is due to collection of more auxin on the light illuminated side of the stem. So cells on that side grow faster. On opposite side cells grow slow to make the stem bend.

Question 2.
Write brief notes on Ivan Pavlov’s experiment on dog to demonstrate conditioned reflexes.
Answer:

• Conditioned reflexes are not inherited.
• Ivan Pavlov, a Russian scientist did experiments on conditioned reflexes. His experiments on dogs have become very famous.
• When the dog sees food, it salivates. He rang a bell whenever the dog was given food.
• After doing this for few days he noticed that the dog salivates when it hears the bell even if the food is not given.
• In other words dog associated the sound of the bell with the food and assumes that whenever the bell rings food is given.
• In expectation of food, saliva starts flowing from its mouth. Human beings are no exception to this.
• For example, standing in attention when you hear National Anthem.

Question 3.
What experimental procedure will you follow to prove phototropism and geotropism in germinating seeds ?
Answer:
Aim : To show phototropism and geotropism in germinating seeds.
Apparatus : Glass jar, soil, bean seed, water.

Procedure:

• Take a glass jar with soil. Sow a bean seed near the wall of the jar.
• After 4-5 days you will notice seed germination.
• Keep the jar under sun. Observe how roots and shoots grow.
• Then tilt the glass jar and keep the plant horizontally for more than 1 week.

Observation :

• Observe the plantlet when plant keeps errect. Shoot will grow towards sun and root towards gravity (soil).
• When keep the plant horizontally, after one week you observe that shoot take tilt grow towards sun and root will grow towards gravity.

IV. Information Skills And Projects

Question 1.
Rangaiah is not feeling well. The following results have come in the tests. Analyse the table. Write answers for the following questions.

1. How can you state that Rangaiah is diabetic?
2. What are the tests to know about Biliru bin?
3. What do you understand from the above report?
4. What questions do you ask the doctor on the above report?
Answer:
1. After blood test it was found that level of glucose (Fasting) is 120 whereas the normal range is 60 – 100. After lunch the level of glucose in blood of Rangaiah further raised to 220, the normal being between 160 – 180. This shows that Rangaiah is diabetic.

2. We can know about bilirubin by blood test.

3. It shows that Rangaiah is diabetic and his systolic pressure ¡s slightly high. The levels of bilirubin ¡n blood also slightly high, almost normal range. Urine test shows sodium levels and at normal range but 24 hours protein is much higher than normal levels.

4.

• What are symptoms shown by Rangaiah as diabetic patient?
• What are the ways to control sugar in the blood?
• Which hormone is responsible for raise of glucose in the blood?
• How sodium maintains blood pressure at normal levels?
• What is the role of bilirubin in digestion?

Question 2.
Write the list of questions to ask the manager of the garden of your village to know which plants are grown through grafting.
Answer:

• What is grafting?
• What are the advantages of grafting?
• What are the plants that can be propagated through grafting?
• Do the plants produced by grafting are susceptible to diseases?
• Give example for plants propagated by grafting.
• What is the time required to obtain grafted plants?
• Can we propagate plants with desirable characters through grafts?
• What is the name of the Plant rooted in the soil?
• What is the name of the plant that is grafted to the rooted plant?
•  How many plants are involved in Grafting?

Question 3.
Explain some major plant hormones and their functions in a tabular form.
Answer:
Some major plant hormones and their actions are given in the following table. Major plant hormones and their actions.

 Hormones Uses Abscisic acid Closing of stomata; seed dormancy Auxins Cell elongation and differentiation of shoots and roots Cytokinins Promote cell division, promotion of sprouting of lateral buds, delaying the ageing in leaves, opening of stomata. Ethylene Ripening of fruit Gibberellins Germination of seeds and sprouting of buds; elongation of stems; stimulation of flowering; development of fruit, breaking the dormancy in seeds and buds.

Question 4.
Observe the information from above the table and answer the questions given below.

i. Which hormone is responsible for reduction of transpiration in plants?
Answer:
Abscisic acid.

ii. What are the hormones that help in growth of plants?
Answer:
Auxins and cytokinins.

iii. What is the use of Ethylene in plants?
Answer:
Help in ripening of fruits.

iv. Which hormone promotes seed dormancy and breaks the dormancy in seeds?
Answer:
Abscisic acid promotes seed dormancy and Gibberellins break the seed dormancy.

v. Which hormone helps in delaying the ageing in vegetable leaves like spinach?
Answer:
Cytokinins delay the ageing of vegetables.

Question 5.
Explain Endocrine glands in a tabular form.
Answer:
Endocrine glands

V. Communication Through Drawing, Model Making

Question 1.
Draw a diagram of Reflex area and describe the functions of different parts of Reflex arc.
Answer:

Functions of different parts of Reflex arc : Reflex arc consists of a receptor, a sensory nerve (afferent) an association neuron or inter neuron, motor nerve (effferent) and an effector organ.

 S.No. Component of the Reflex arc Function 1. Receptor Receives information and generates impulses. 2. Sensory (Afferent) nerve Carries information from the receptor to the inter neurons in the spinal cord. 3. Inter neurons Processes’ the information and generates responses. 4. Motor (efferent) nerve Carries the information from the spinal cord to the effector organ. 5. Effector organ Receives the information from the efferent neuron and shows the appropriate response.

Question 2.
Draw a diagram of a plant showing phototropism. Explain why plants possess such type of response.
OR
A plant which grows near a window bends towards sunlight. Write the reason for it.
Answer:

• The response of a plant to light is called phototropism.
• The plant stem responds to light and bends towards it due to the action of auxin hormone.
• When the light falls only on the right side of the stem, then the auxin hormone collects in the left side of the away from light. This is because auxin hormone prefers to stay in shade.

Question 3.
Draw the diagram of afferent nerve and label the parts.
Answer:

Question 4.
Draw the neuron which carries messages from brain / spinal cord to muscles.
Answer:

Question 5.
The diagram given below depicts the cross-section of the spinal cord. Label the parts.
Answer:

Answer:
1. Dorsal root
2. Spinal nerve
3. Ventral horn
4. Dorsal horn
5. Motor nerve

Question 6.
Draw a block diagram of different nerve pathways.
Answer:

VI. Appreciation And Aesthetic Sense, Values

Question 1.
How will you appreciate the co-ordination among different organs of your body?
Answer:

• When you crossing a road, eyes and ears will see and listen to the voice.
• Through brain and motor nerve, legs will receive information to cross the road.
• With help of eyes, ears, legs, hands and body (co-ordinated by brain, spinal cord, sensory nerves and motor nerves) you can cross road safely.
• If co-ordination misses among different organs of our body, you may not complete task successfully.

VII. Application To Daily Life, Concern To biodiversity

Question 1.
How does our body maintain blood sugar level?
Answer:

• The timing and amount of hormone released are regulated by feedback mechanisms.
• When the sugar levels in blood rise, they are detected by the cells of the pancreas which respond by producing more insulin.
• If the blood sugar level falls, insulin secretion is reduced.

Question 2.
Many youngsters in our state are dying with head injury when they meet with bike accidents i.e. damage to brain. To motivate people to wear helmet, write slogans.
Answer:

• Wear helmet – Save life.
• Human brain is very precious – Save it by wearing helmet.
• Youngsters – Helmet is your life guard.
(It is open ended question. You can add some more slogans based on concept.)

## TS 10th Class Biology Important Questions 3rd Lesson Transportation

These TS 10th Class Biology Chapter Wise Important Questions 3rd Lesson Transportation will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 3rd Lesson Transportation

1 Mark Question

Question 1.
Two person’s Blood Pressure is like this:

 Ramaiah 140/80 Rangaiah 110/90

Whose Blood Pressure is high ? What does It Indicate?
Answer:
The normal blood pressure is 120/80
The numerator 120 indicates systolic pressure.
The denominator 80 indicates diastolic pressure.
Ramaiah B.P. Is 140/80. So he has high blood pressure.

Question 2.
How does lymph differ from blood?
Answer:

• RBC are present in blood, RBC are absent in lymph.
• Blood is Red in colour, lymph is colourless.

Question 3.
Name the largest artery in the body.
Answer:
Aorta is the largest artery in the body.

Question 4.
What happens If platelets are absent in the blood?
Answer:
If platelets are absent in the blood, then

• blood doesn’t clot.
• blood flows continuously.

Question 5.
Name the apparatus, shown in the figure below.

Answer:
Sphygmomanometer.

Question 6.
List out the materials you have used to observe the goat heart in your laboratory.
OR
Write any two materials needed for an experiment to examine a mammal heart.
Answer:

• Freshly collected specimen of goat’s heart
• Soda straws
• Used pen refus
• Sharp and long blade
• Tray
• A jug of water
• Dissection scissors
• Forceps
• Gloves

Question 7.
Prepare two questions, which you ask the doctor to know more details about high blood pressure.
Answer:

• How can we know that we have high blood pressure?
• What are the adverse affects of high blood pressure?
• How can we prevent high blood pressure?
• What diet should you prescribe for high B.P patients?

Question 8.
Name any two valves present in human heart.
Answer:

• The valve that is present between left atrium and left ventricle is mitral valve or bicuspid valve.
• The valve that is present between right atrium and right ventricle is tricuspid valve.

Question 9.
Siri injured while playing, and the blood is flowing continuously from wound, what may be the reason for this?
Answer:

• Vitamin – K is helpful for clotting of blood. Perhaps Sin might be suffering from deficiency of Vitamin – K. So, blood is flowing continuously from the wound.
• He may be suffering from thalassemia.

Question 10.
What is the size of our heart ?
Answer:
It is approximately size of our fist.

Question 11.
What is the shape and structure of heart ?
Answer:
The heart is a pear shaped structure, triangle in the outline, wider at the anterior end and narrower at the posterior end.

Question 12.
Which protects the heart from shocks ?
Answer:
The space between the two layers of pericardial membrane is filled with pericardial fluid, protects the heart from shocks.

Question 13.
What is cardiac cycle ?
Answer:
One contraction and one relaxation of atria and ventricles is called one – cardiac cycle.

Question 14.
In which organism protoplasm shows Brownian movements ?
Answer:
Amoeba

Question 15.
The digestive system is highly branched and supplies digested food to all the cells in ?
Answer:
Platyhelmenthes.

Question 16.
Which has taken up the function of collection and distribution of materials in Nemafyhelmenthes ?
Answer:
Pseudocoelom.

Question 17.
What is lymphatic system ?
Answer:
Lymphatic system is a parallel system to venous system which collects tissue fluid from tissues and transports it to the venous system.

Question 18.
What is lymph ?
Answer:
Lymph is the substance that contains blood without solid particles.

Question 19.
What is tissue fluid ?
Answer:
To supply nutrients to the cells the liquid portion of the blood with nutrients flows out of the capillaries. This is called tissue fluid.

Question 20.
What is double circulation ?
Answer:
If the blood flows through the heart twice for completing one circulation, it is called double circulation.

Question 21.
What is hypertension ?
Answer:
People who have B.P more than 120/80 during rest period are said to have hypertension.

Question 22.
What is serum ?
Answer:
The straw coloured fluid portion after formation of the blood clot is called serum.

Question 23.
Which vitamin is required for blood clot ?
Answer:
Vitamin – K

Question 24.
What is haemophilia ?
Answer:
Due to genetic defect, the blood may not coagulate or clot. This type of defect is called haemophilia.

Question 25.
In root where was xylem tissue situated ?
Answer:
Xylem tissue was situated towards the centre of the root.

Question 26.
Where do we find xylem in stems ?
Answer:
In stems, xylem was arranged in vascular bundles near the outside.

Question 27.
Which process plays an important role in absorption of water by root hairs ?
Answer:
Osmosis

Question 28.
What is transpiration ?
Answer:
Evaporation of water through stomata of leaves is called transpiration.

Question 29.
Which tissue transports food to all the other parts of the plant ?
Answer:
Phloem

Question 30.
Which tissue transports water to all the other parts of the plant ?
Answer:
Xylem

Question 31.
Which organ acts as a pump in the circulatory system ?
Answer:
Heart

Question 32.
Name two liquids which help in the transport of substances in the human body.
Answer:
Blood and lymph.

Question 33.
Name the two types of transport systems in human beings.
Answer:
Circulatory system and lymphatic system.

Question 34.
Name the two parts of a plant through which its gaseous waste products are released into the air.
Answer:
Stomata in leaves, lenticels in stem.

Question 35.
What does the pulse rate show ?
Answer:
Pulse rate shows the number of heart beats, the mechanism of heart beating and also the flow of blood in the blood vessels.

Question 36.
How many layers are covering the heart ?
Answer:
The heart is covered by two layers of membranes. They are called pericardial membranes.

Question 37.
Which end of the heart is broader and which end is narrow ?
Answer:
Heart is wider at the anterior end and narrow at the posterior end.

Question 38.
Why are the artery walls very strong and elastic ?
Answer:
Because they are carrying blood away from the heart to every cell of the body tissues and are doing with a lot of pressure. So the walls are thick to enable it to do its job and they are elastic.

Question 39.
What is the function of Gastro vascular cavity ?
Answer:
Digestion and transportation of nutrients to each cell of the body in cnidarians.

Question 40.
Which animals are encouraged by foresters to keep down the population of voles and rabbits ?
Answer:
Foxes, Badgers, Hawks, Owls.

Question 41.
Which animals do great damage particularly to beech and sycamore ?
Answer:
Grey squirrels.

Question 42.
When do you think that our pulse rate goes up ?
Answer:
Our pulse rate increases after jogging, running, strenuous exercise, during fear, anxiety, and suffering from fever.

Question 43.
Sometimes barks of the tree damaged more than a half, even though tree is alive. How is this possible ?
Answer:
On the outside of cambium phloem is present. To the centre of the tree xylem is present.
There is no obstruction to flow of water in the damaged tree. Hence it survives.

Question 44.
Which of the four chambers of the human heart has the thickest muscular walls?
Answer:
Right ventricle.

Question 45.
Name the conducting tissue of plants which is made of sieve tubes along with companion cells.
Answer:
Phloem.

Question 46.
What factors contribute to rate of transpiration ?
Answer:
Number of leaves, number of stomata, temperature of surroundings, wind, water supply, amount of light, etc.

Question 47.
How does transpiration pull help in ascent of sap ?
Answer:
Water column build up as a result of cohesion and adhesion forces. The negative pressure in the upper tissues results in upward pull of water.

Question 48.
What is translocation?
Answer:
The transport of food from the leaves to other parts of the plant is called translocation.

Question 49.
Sweating in animals is equivalent to what in plants ?
Answer:
Transpiration.

2 Mark Question :

Question 1.
Neelima conducted an activity on her friends and got the following results.
Answer:

 S.No. Name Heart beat at rest/min Heart beat after jogging / min Pulse rate at rest / min 1. Jeevan 72 109 72 2. Raju 75 110 74 3. Reshma 73 111 73

i. What is the relation between heart beat and pulse rate?
ii. Why is the heart beat rate more after Jogging?
Answer:
i. Heart beat rate Is equal to pulse rate.
ii. In the jogging muscles need more oxygen to produce high energy. To supply this oxygen heart beat is increased alter jogging.

Question 2.
A person is injured while playing on the ground. Blood is flowing continuously. What might be the reasons?
Answer:
In this case blood is not clotting. Because

• He may be suffer from ‘Haemophilia’.
• Blood platelets are less in number.
• He may suffer from vitamin K deficiency.
• Enzyme ‘Thrombokinase’ may not release.

Question 3.
Where are the valves located in human heart? Write their names.
Answer:
Valves present in human heart

 Name of the valve Location Allows blood to flow from 1. Tricuspid Valve Right auriculoventricular septum Right atrium to right ventricle. 2. Bicuspid Valve (Mitral Valve) Left auriculoventricular septum. Left atrium to left ventricle. 3. Pulmonary Valve At the origin of pulmonary aorta in the right ventricle. Allows blood to flow from right ventricle into pulmonary aorta. 4. Systemic Valves (Aortic Valves) At the origin of systemic- aorta. Allows blood to flow from left ventricle into the systemic aorta.

Question 4.
What happens if there are no valves in veins?
Answer:

• If the valves are absent in veins blood will not flow in uni-direction and flows backward too.
• Blood will not supplied to heart properly.
• Bulging of veins may takes place.

Question 5.
Which items do you take into consideration to explain the differences of arteries and veins?
Answer:
I would like to consider the following items to explain the difference between arteries and veins. They are thickness of walls, valves, capacity to retain shape when blood is absent, direction of blood flow, pressure in the vessels, type of blood transported, type of blood carried by pulmonary artery and type of blood carried by pulmonary vein.

Question 6.
When you know the heart pumping method is circulatory system, which issue did you remember particularly ? What’s the reason for that ?
Answer:
The heart beats faster during and after an exercise remembered by me. Because at that time our body needs more energy under these conditions. The faster breathing of heart pumps blood more rapidly to the body organs which supplies more oxygen to the body cells for rapid respiration to produce more energy. That is a hefty job for a fist sized muscle.

Question 7.
Classify different types of blood vessels in humans. On what bases you classify blood vessels ?
Answer:

• There are three types of blood vessels called arteries, veins and capillaries present in humans.
• These blood vessels are classified on the basis of thickness of walls, valves, capacity to retain shape when blood is absent, direction of blood flow, pressure in the vessel, type of blood transported, type of blood carried by pulmonary artery or vein.

Question 8.
Anil fell down in going to school got knee injury, start bleeding after some time he was wondered by seeing blood clot ? Why blood clotted ?
Answer:
Blood clotting normally occurs when there is damage to blood vessel. Platelets immediately begin to adhere to the cut edges of the vessel and release chemicals to attract even more platelets. A platelet plug is formed and the external bleeding stops.

Question 9.
Describe the blood vessels that carry away blood from human heart.
Answer:

• The rigid vessels called arteries which originate from the heart supply blood to various organs in the body.
• From the upper part of the left ventricle a thick blood vessel called aorta arises. It supplies oxygenated blood to the body parts.
• From the upper part of the right ventricle pulmonary artery arises that supplies deoxygenated blood to the lungs.
• A pair of coronary arteries (vessels) carry oxygenated blood to the muscles of heart.
• All the arteries carry oxygenated blood except pulmonary artery.

Question 10.
How is the human heart protected from shocks or injuries ?
Answer:

• Heart is located between the two lungs protected by rib cage.
• The human heart is covered by two layers.
• These membranes are called pericardial membranes.
• The space between the two layers is filled with pericardial fluid.
• The pericardial fluid protects the heart from physical shocks or injuries.

Question 11.
When do we hear the sounds of ‘lubb’ and ‘dubb’ from the heart ?
Answer:

• On ventricular contraction due to pressure, the blood moves into the aorta and pulmonary artery.
• The aperture between the atria and ventricles is closed by valves.
• When the valves are closed forcibly, we can listen to the first sharp sound of the heart ‘lubb’.
• When the ventricles start relaxing the pressure in the ventricles is reduced.
• The valves which are present in the blood vessels are closed to prevent backward flow of blood into the ventricles.
• Now we can listen to a dull sound of the heart ‘dubb’.

Question 12.
What is cardiac cycle ? How does it occur ?
OR
Blood is /towing in blood vessels continuously from heart to all parts of body.
What is cardiac cycle ? Explain different phases of cardiac cycle.
Answer:

• The sequential events in the heart which are cyclically repeated are called cardiac cycle.
• The cardiac cycle includes an active phase systole and a resting phase the diastole of atria and ventricles.
• The contraction phase of the heart beat is called systole and the relaxation phase of heart beat is diastole.
• The whole process of cardiac cycle is completed in approximately 0.8 seconds.
• The time needed for atrial contraction is 0.11-0.14 seconds.
• The time needed for ventricular contraction is 0.27-0.35 seconds.

Question 13.
Write the differences between single circulation and double circulation.
Answer:

 Single circulation Double circulation 1. Blood flows through the heart only once for completing one circulation. 1. Blood flows through the heart twice for completing one circulation. 2. Pulmonary circulation is absent. 2. Pulmonary circulation is present. 3. Heart consists of two chambers. 3. Heart consists of three or four chambers. 4. Single circulation is seen in fishes. 4. Double circulation occurs in frogs, reptiles, birds and mammals.

Question 14.
What are the components of the transport system in highly organised plarts ?
Answer:

• The transport system of organised plants consists of xylem and phloem.
• Xylem which has vessels and trachieds transports water and minerals from root to other parts of the plant.
• Phloem which consists of sieve tubes, sieve cells and companion cells transports food from leaves to storage organs and other parts of the plants.
• In xylem the transport is unidirectional i.e., from root upward while in phloem it is bidirectional.

Question 15.
State the role and function of lymph in human transport system.
Answer:
Lymph is a circulatory fluid. It flows in lymph vessels.

• Lymph (is also called tissue fluid. is colourless.
• It consists of lymphocytes which kill germs and protect the human body from infections.
• Lymph carries digested and absorbed fat from intestine.
• It drains excess fluid from extra cellular space back into the blood.
• Its flow is unidirectional i.e., from tissues → lymph capillaries → vein → heart.

Question 16.
Write the differences between blood and lymph.
Answer:

 Blood Lymph 1. Reddish in colour. 1. Pale yellow in colour. 2. Red blood cells are present. 2. Red blood cells are absent. 3. Bidirectional flow. 3. Unidirectional flow. 4. Flow is rapid. 4. Flow is slow. 5. Leucocyte count relatively less. 5. High leucocyte count. 6. Platelets present. 6. Platelets absent.

Question 17.
A certain tissue in a green plant somehow gets blocked and the leaves wilted. What was the tissue that got blocked ?
Answer:

• The tissue that got blocked may be xylem. It is through the xylem that water and minerals absorbed by roots from the soil are transported to the leaves and other parts of the plant.
• So if xylem is blocked, the leaves will not get the nourishment and will get wilted.

Question 18.
How does transpiration help plants ?
OR
Transpiration is necessary evil. Explain.
Answer:

• During transpiration the evaporating water carries away heat energy. Thus it cools the temperature of plants.
• Due to water loss the osmotic pressure inside leaves decreases. Due to which water and other minerals are able to reach leaves from roots and stem.

4 Mark Question :

Question 1.
What is a Cardiac cycle? Explain the steps involved in it.
Answer:
Cardiac cycle : One contraction and one relaxation of atria and ventricles is called one cardiac cycle.
(Or)
The sequential events in the heart which are cyclically repeated are called cardiac cycle.

Steps:
1. Relaxation of atila and ventricles: AH the tour chambers of the heart are in relaxed state (diastole).

2. Blood flows into atila : Blood from venacava and pulmonary veins enters the right and left atria respectively.

3. Contraction of atila and flow of blood into ventricles: The atria contract, forcing the blood to enter into the ventricles.

4. Contraction of ventricles (Lub) : When the ventricles are filled with blood they start contracting and atria start relaxing. The aperture between the atria and ventricLes is closed by valves.

5. Relaxation of ventricles (Dub): When the ventricles start relaxing the pressure in the ventricles reduced. The blood which has entered the arteries tries to come back into the ventricles. The valves which are present in the blood vessels are closed to prevent backward flow of blood into the ventricles.

Question 2.
What questions do you ask your teacher to know about the coagulation of the blood?
OR
What questions do you pose to your teacher to understand ‘blood clotting’?
Answer:

• What is coagulation?
• How blood coagulates?
• What are the factors responsible for coagulation?
• What happens if coagulation occurs in blood vessels?
• Which substance prevents coagulation of blood in blood vessels?
• Which vitamin is required for coagulation of blood?
• What happens if coagulation of blood does not occur when we meet with accidents?
• Which cells present in blood help in coagulation of blood?

Question 3.
Describe the internal structure of heart with a neat labelled diagram.
OR
What is called pumping station in human body? Explain its structure with suitable diagram.
Answer:

• Heart is called pumping station in human body.
• Internally heart is divided into four parts by grooves.
• Two upper parts are called atria, and the lower ones are called ventricles.
• The two atria are separated from each by inter-atriolar septum and the right and
left ventricles are separated from each other by inter-ventricular septum.
• The inter-atriolar septum and inter-ventricular septum prevent mixing of deoxygenated blood in the right side of the heart with oxygenated blood in the left side of the heart.
• The walls of the ventricles are relatively thicker than atrial walls
• The largest artery is the aorta which arises from the left ventricle supplies blood to all the body parts except lungs.
• Pulmonary artery that arises from the right ventricle carries deoxygenated blood to lungs.
• The right atrium and right ventricle are connected to each other by right atrioventricular aperture.
• The left atrium and left ventricle are connected to each other by left atrioventricular aperture.
• Tricuspid valve guards the right auriculoventricular aperture and mitral valve or bicuspid valve guards the left atrioventricular aperture.
• Blood from the anterior parts of the body is collected by superior venacava which opens into right atrium.
• Blood from the posterior parts of the body is collected by inferior venacava or post-cava vein which also opens into right atrium.
• Coronary arteries supply blood to the muscles of the heart whereas coronary veins collect blood from the heart. It also opens into right atrium.

Question 4.
Read the table and answer the following questions.
Answer:

 S.No. Name of the Phylum Type of transport system 1. Cnidarians Gastro vascular cavity 2. Platyhelminthes Digestive system 3. Nematyhelminthes Pseudocoelom 4. Annelida Blood vessels 5. Arthropoda Open circulatory system

i. In which phylum, blood vessels are first formed ?
ii. In which phylum, organisms have haemoglobin in their blood ?
iii. In which phylum, digestive system helps in transportation ?
iv. Why do Arthropods have open circulatory system ?
Answer:
i. Blood Vessels first formed in Annelida phylum.
ii. Organisms in Annelida phylum have haemoglobin in plasma.
iii. Cnidarian phylum of digestive system helps in transportation.
iv. In Arthopods blood vessels are absent, sinuses are present. So they have open circulatory system.

Question 5.
Write about the valves, their positions, their functions in human heart. How many blood vessels are attached to heart ? Write about their positions and functions.
Answer:
Valves and their positions in Human heart:

• The valve present in between Right artery and Right ventricle is Tricuspid valve.
• The valve present in between Right atrium and Right ventricle is Bicuspid valve.
• The valves present at the region of pulmonary arota is called Pulmonary valves.
• The valves present at the region of systemic arota is called systemic valves.

Blood vessels attached to the heart their positions and functions :

• The blood vessels found in the walls of the heart are coronary vessels which supply blood to muscles of the heart.
• From the upper part of the left ventrical arota arises it supplies oxygenated blood to the body parts.
• From the upper part of the right ventricle pulmonary artery arises which supplies oxygenated blood to the lungs.
• The vein which is right side of the heart is superior venacava.
• The vein which is coming from the posterior part of the heart is inferior venacava which collects blood from posterior part of the body.

Question 6.
Write a short note on Human Lymphatic System and its functions.
(OR)
What is lymph ? What are the functions of it ?
Answer:

• Lymphatic system consists of lymph capillaries, lymph vessels, lymph nodes and lymph glands.
• To supply nutrients to the cells (tissues), the liquid portion of the blood with nutrients flows out of the capillaries. This is called tissue fluid.
• This fluid flows through a system called as lymphatic system. The fluid mainly returns back into the blood stream.
• Lymph is the vital link between blood and tissues by which essential substances pass from blood to cells and excretory products from cells to blood.
• Lymph is the substance that contains blood without solid particles.
• From intercellular spaces, lymph goes into lymphatic capillaries.
• Lymphatic capillaries join to form large lymph vessels which finally open into larger veins.
• Lymph flows only in one direction, that is from tissues to heart through veins.

Functions of Lymph :

• Lymph carries digested and absorbed fats from small intestine to different tissues of the body.
• It helps in removing waste materials from the cells in the body to drain into blood.
• Lymph protects cells in the tissues from infection.

Question 7.
Explain the process of coagulation of blood.
Answer:

• When the blood flows out from injuries, the platelets release an enzyme called thrombokinase.
• Thrombokinase acts on another substance present in the blood called prothrombin converting it into thrombin.
• Thrombin acts on another substance called fibrin, that is present in dissolved state converting it into insoluble fibrin.
• The blood cells entangle in the fibrin fibers forming the clot.
• The fibrin fibers are attached to the edges of the wound and pull them together.

I. Conceptual Understanding:

Question 1.
Observe the given diagram. Which type of cardiac cycle it indicates? Explain the process that happens here.
Answer:
1. It indicates double circuit circulation. It includes pulmonary circulation and systemic circulation.

2. Here blood flows through the heart twice for completing one circulation. Hence it is called double circulation.

3. In this circuit deoxygenated blood from organs of body is collected into the right auricle and then sent into right ventricle. From right ventricle blood is pumped to the lungs. In the lungs blood is oxygenated and is returned to the left auricle by pulmonary vein. This circulation is known as pulmonary circulation.

4. In systemic circulation the oxygenated blood from the left auricle is pumped into the left ventricle. From the left ventricle blood is pumped into the systemic aorta. This aorta supplies blood to various organs of the body.

Question 2.
In human body “A” is a pumping organ. From lungs blood vessel “B” with oxygenated blood enters upper “C” part of left chamber of the organ. When “C” chamber contracts blood flows into “D” lower left chamber. “D” chamber contracts blood is pumped to all parts of the body except lungs through blood vessel E. Deoxygenated blood from body parts is collected by blood vessel “F’ and opens upper “G” right chamber. This chamber contracts blood flows “H” lower chamber. Lastly “H” contracts Deoxygenated blood sent to lungs by blood vessel “I”.
a. “A” represent what organ ?
b. (i) B (ii) E (iii) F and (iv) I are what blood vessels ? Write their names.
c. (i) C (ii) D are what chambers ?
d. (i) G (ii)Hare what chambers ? Write their names.
Answer:
a. Heart

b.
i. B – Pulmonary vein
ii. E – Systemic aorta
iii. F – Superior or Inferior venacava
iv. I – Pulmonary artery

c.
i. C – Left atrium
ii. D – Left ventricle

d.
i. G – Right atrium
ii. H – Right ventricle

Question 3.
Write about the blood vessels that bring blood to human heart.
Answer:

• The less rigid vessels called veins bring blood from body parts to the heart.
• There are three large blood vessels or veins that carry blood to heart from all the
body parts.
• The vein that collects blood from the upper parts of the body is called superior venacava. These caval veins open into right atrium.
• The vein that collects blood from the lower or posterior part of the body is called post caval vein or inferior venacava.
• The third vein called pulmonary vein brings oxygenated blood from the lungs and open into left Auricle.
• The right atrium receives deoxygenated blood while the left atrium receives oxygenated blood from lungs.
• In addition to these veins a pair of veins called coronary veins brings deoxygenated blood from the walls of the heart. They also open into right atrium.

Question 4.
What is blood pressure ? How is it measured ?
Answer:

• The pressure with which the blood flows in the blood vessels is known as blood pressure.
• Blood pressure is measured in the upper arm artery.
• There are two pressure readings.
• One measures the strongest pressure during the time blood is forced out of the ventricles. This is called systolic pressure.
• For a healthy young adult it will be 120 mm of Hg.
• The second reading is taken during the rest period, as the ventricles refill with blood. This is called diastolic pressure.
• The diastolic pressure will be 80 mm of Hg.
• Doctors measure the blood pressure with a device called sphygmomanometer.

Question 5.
What is the need of special tissues or organs for transport of substances in plants and animals ?
Answer:

• The body of plants and animals is made of cells.
• In order to survive and maintain themselves, all cells require oxygen, water and food.
• They need certain other substances to carry out various life processes.
• Oxygen, water, food or any other substances may be picked up at one end of the body of an organism and transported to other parts.
• Thus transportation is a life process in which a substance absorbed or synthesised in one part is moved to other parts of the body.
• The methods of transportation of substances are different in plants and animals.
• Therefore there is a need of special tissues or organs for transport of substances in plants and animals.

Question 6.
Explain the process of transport of mineral salts.
Answer:

• Mineral salts are necessary for plant nutrition and that they are obtained from the soil in solution through the root hairs.
• The salts are in the form of electrically charged ions.
• Sodium chloride (NaCl) is in the form of Na+ and Cl and Magnesium Sulphate (MgSO4 occurs as Mg2+ and SO42-.
• But, they are not absorbed into the root hairs by the simple process of diffusion, but it must involve the use of energy by the cytoplasm.
• Once ions are absorbed, the ions travel with water in the xylem vessels and pass to the growing parts of the plants where they are used for growth.
• They may also pass laterally from xylem to phloem.

Question 7.
Write about the changes in the evolution of transport system in animals.
Answer:
1. In Amoeba due to Brownian movements nutrients and oxygen are distributed throughout the protoplasm equally.

2. The parazones like sponges, use sea water for transportation. Sponges create their own currents by beating of flagella that are present in their body.

3. Cnidarians developed blind sac like gastrovascular cavity, which has taken up the function of digestion and transportation of nutrients, e.g.: Hydra and jelly fish.

4. In platyhelmenthes, the digestive system supplies digested food to all the cells directly, excretory system collects wastes from each cell individually.

5. In animals belonging to Nematyhelmenthes the pseudocoelom has taken up the function of collection and distribution of materials.

6. In Annelids, animals have developed a pulsative vessel to move the fluid and the transporting medium is blood.

7. In Arthropods have developed a pulsative organ to pump the blood. The blood floods the tissues, directly supplying the nutrients to the tissues.

8. Transportation system which supplies nutrients to the tissues directly is called open type of circulatory system. e.g.: Arthropods, many mollusks and lower chordates.

9. The other type of transportation system where the blood takes the responsibility of delivering the materials, which flows in the blood vessels is called closed type of circulatory system.

10. Such type of closed circulatory system is present in annelids, echinoderms, cephalopod mollusks and all the higher animals.

Question 8.
How are water and minerals transported in plants ?
Answer:

• Xylem tissue transports water and mineral salts in plants.
• Xylem vessels and tracheids of root, stem and leaves are interconnected to form a continuous system of water and minerals conducting channels to each part of the plant.
• The cells of root hair present in the soil absorb water from the soil by osmosis.
• The entry of water dilutes the contents of the root hair vacuole so that it becomes weaker than its neighbour.
• Therefore water passes into the neighbouring cell which in turn becomes diluted, finally water enters the xylem vessel.
• This creates a column of water that is steadily pushed upward, called root pressure.
• Root pressure is not enough to push water and dissolved minerals to leaves in the tall trees.
• There is a continuous loss of water through stomata of the leaves in the form of water vapour. This process is called transpiration.
• The water lost due to transpiration is taken up from the xylem vessels and tracheids
in the leaves.
• This loss of water during transpiration creates a suction pressure which pulls water from the xylem cells of roots.
• This results in enhanced absorption and upward movement of water and dissolved minerals from roots to the leaves due to transpiration.
• At night when stomata are closed root pressure has an effect on transportation of water.
• Transpiration pull is the major force in the movement of water and dissolved minerals in the xylem during daytime.

Question 9.
How is manufactured food in leaves transported to other parts of the plant ?
Answer:

• Food such as sugar is synthesised in the green parts of plants mainly leaves to be transported to actively growing and those which stores food.
• Phloem is the tissue responsible for transport of food material.
• The transport of soluble product of photosynthesis through phloem is known as translocation.
• The transport of prepared food and other substances takes place both in upward and downward directions.
• The translocation is an active process and utilizes energy.
• Entry of food material into phloem tissue causes increase in osmotic pressure, as a result water from outside moves into phloem.
• The osmotic pressure moves the dissolved material in the phloem to tissues which have less pressure.
• Thus material moves in phloem, mainly in sieve tubes, to place of need in the plant body.
• In plants sugar is translocated from its storage organs like root or stem to growing regions which need energy.

II. Asking Questions And Making Hypothesis:

Question 1.
If you get chance to meet a cardiologist / cardiovascular surgeon, what questions you will ask about the problems related to heart ?
Answer:
I will ask following questions to clarify my doubts about problems related to heart.

• Why heart is very vital organ ?
• If we do strenous exercise, will it tired quickly ?
• Why do we get heart attack ?
•  What are causes for heart attack ?
• What precautions shall we take, to prevent heart attack ?
• What is stunt ?
• When do a person need stunt ?
• What is by-pass surgery ?
• What is pace maker ?
• What type of food habits prevent heart related problems ?
• Why heart beat always not stable ?

Question 2.
What happens if valves between left auricle and left ventricle does not work properly ?
Answer:

• Pumping of oxygenated blood to different parts of body from the left ventricle may not occur properly.
• Blood may re-enter into left auricle hence systolic pressure may not maintain properly.

Question 3.
What happens the concentration of solution in root hair cell is less than the soil water ?
Answer:

• Water from root hair cell comes out in to soil water.
• Water may not enter into the root hair cell and pass on to xylem.

Question 4.
What would happen if cell sap in the cells of root hair contain high concentration of ions ?
Answer:

• Cell sap of root hair cells contain high concentration of ions pass from cell to cell by osmosis through the epidermis, root cortex, endodermis and reach the root xylem.
• The xylem vessels of the root of the plant are connected to the xylem vessels of its stem.
• The water containing dissolved minerals enter from the root xylem vessels into stem xylem vessels.
• So the cell sap containing water and minerals carried by the xylem vessels in the stem reach the leaves through the branched xylem vessels which enter from the petiole into each and every part of the leaf.
• In this way the cell sap of root hair cells containing high concentration ions reach through the root and stem to the leaves of the plant.

III. Experimentation And Field Investigation:

Question 1.
Write briefly about the work done by William Harvey on circulation of blood.
Answer:

• William Harvey was an Englishman who after became a doctor went to Italy for further education.
• Harvey dissected the hearts of dead people and studied the valves between each atrium and its ventricle.
• Harvey noticed that they were one way valves which allow blood to flow from atrium to the ventricle, but not from ventricle into the atrium.
• He also noticed that all the veins in the human body allows blood to flow towards heart.
• Harvey also identified that the blood flows through the heart twice in human beings. Hence it is called double circulation.
• Harvey also showed that it was impossible to suppose that the blood was used up in the body and that new blood was formed.
• He found that in one hour, the heart pumped out a quantity of blood that was three times the weight of a man.
• The same blood had to circulate and be used over and over again.

Question 2.
What was the classical experiment conducted by William Harvey to demonstrate movement of blood in veins ?
OR
How do you repeat the classical experiment to demonstrate the movement of blood in veins ?
Answer:

• In early 17th century William Harvey conducted an experiment to demonstrate the movement of blood in veins.
• Tie a tornquit just above the elbow of a person, whose blood vessels are prominent in the hand.
• Ask him/her to hold a firm support as shown in the figure. Now the blood vessels can be seen more prominently.
• Locate a prominent bluish blood vessel.
• At the end of the vessel farthest from the elbow apply steady pressure, so as to close its cavity.
• Now apply pressure from elbow towards the palm slowly and observe the changes in the blood vessels.
• Remove the pressure.
• Apply pressure from palm to wards elbow and see what happens.

Question 3.
Write an experiment to illustrate the conduction of sugars by phloem.
Answer:

• Experiments to illustrate the conduction of sugars by the phloem have been done by removing a ring of bark from a shoot to expose the wood.
• Remove all tissues from the cambium outwards including the phloem.
• After a few days, when the tissues above and below the ring were analyzed.
• it was shown that food had accumulated above the ring but was not present below it.
• If it is left for sometime, the stem increases in thickness immediately above the ring, but no growth occurred below it.
• So, any damage to the phloem all around the stem will prevent food from passing down to the roots and the tree will eventually die.

V. Information Skills And Projects:

Question 1.
Observe following table and answer questions given below.

 Name of the animal Weight of the body Weight of tine heart No, of beats/min Blue whale 1,50,000 kg 750 kg 7 Elephant 3000 kg 12-21 kg 46 Man 60 – 70 kg 300 gm 76 Coaltit (Bird) 8 gm 0.15 gm 1200

i. In which animal the heart beat rate is very slow ?
Answer:
In Blue whale heart beat rate is slow.

ii. What is weight of human heart and heart beat rate ?
Answer:
Weight of human heart is 300 gms and heart beat rate is 76/min.

iii. Which animal has highest heart beat rate ?
Answer:
Coaltit (Bird)

iv. Is there any relation between weight of the body and heart beat rate ?
Answer:
Yes, there is a relation between body weight and heart beat rate. If the body weight is more heart beat rate is less. If the body weight is less, the heart beat rate is more.

Question 2.
Group of students conducted an activity and got following results.

 S.No. Name of the student At rest After jogging Heart beat/ minute Pulse rate/ minute Heart beat/ minute Pulse rate/ minute 1. Raju 76 76 118 119 2. Rama 78 77 120 120 3. Manjula 78 76 121 121 4. Shankar 77 78 132 131 5. Rajasekhar 77 77 135 135

i. What is the relation between heart beat and pulse rate at rest ?
Answer:
Pulse rate and heart beat always equal at rest.

ii. Why heart beat rate is more after jogging ?
Answer:
After jogging body cells need more energy. It need more respiration (oxygen).
Through heart, blood flows at high speed ultimately rate of breathing, heart beat and pulse rate increases rapidly.

V. Communication Throught Drawing, Model Making:

Question 1.
Draw T.S. of flow of blood in arteries and veins. Write flow of blood in between them.
OR
Write the differences between T.S. of artery, T.S. of vein and T.S. of blood capillary.
Answer:

• Arteries carry blood from the heart to body parts. Veins carry blood from body organs to heart.
• Veins collects deoxygenated blood from all body parts into the right atrium. Pulmonary vein brings oxygenated blood from lungs into left atrium.
• Blood capillaries are the microscopic vessels that connect smallest arteries and veins.

Question 2.
Draw neat labelled diagram of L.S of human heart. What is the function of pulmonary artery ?
Answer:

Question 3.
The diagrams given below shows cross-section of two kinds of blood vessels.

i. Identify the blood vessels A and B. In each case, give reasons to support your answer.
Answer:
‘A’ is T.S. of artery and ‘B’ is T.S. of vein.
Artery walls are thick, the shape of it’s wall is retained when blood is absent.
Veins walls are thin, and the shape of it’s wall is collapsed.

ii. Name the parts numbered 1 and 2.
Answer:
Name of part 1 is muscle layer and 2 is lumen.

Question 4.
Draw the diagrams of single and double circulation blood systems.
Answer:

VI. Appreciation and Aesthetic Sence,Value

Question 1.
How will you appreciate function of Human heart since 21st day of embryonic stage to till death ?
Answer:

• Heart beat starts since 21st day of conception and by the day of birth it function fully.
• Heart beat denotes state and condition of human body.
• Heart is most amazing organ of human body which works even if you take rest.

VII. Application to Daily Life, Concern to Biodiversity:

Question 1.
After learning about circulatory system, what changes would you like to bring in your life style ?
Answer:
I will bring following changes in my life style.

• I will avoid heavy fat food and junk food.
• Try to spend stress free life as stress leads where to cardiac problems.
• I will do regular physical exercise or work to keep my self fit.
• Keep away from bad habits like smoking and alcohol consumption.
• After 40 years, yearly twice I will consult cardialogist.

## TS 10th Class Biology Important Questions 2nd Lesson Respiration

These TS 10th Class Biology Chapter Wise Important Questions 2nd Lesson Respiration will help the students to improve their time and approach.

## TS 10th Class Biology Important Questions 2nd Lesson Respiration

1 Marks Questions

Question 1.
Fermented idli, dosa produces smell. Name the microorganism responsible for producing such smell?
Answer:
Yeast is responsible for producing such smell in fermented idli, dosa

Question 2.
In what compound, the energy released during the breakdown of glucose, is stored?
Answer:
“ATP” (Adenosine Triphosphate).

Question 3.
Label a and b in the given diagram.

Answer:
a. Matrix
b. Cristae.

Question 4.
Name chemical substances produced in human muscles during Anaerobic respiration.
Answer:
Lactic acid is produced in human muscles during Anaerobic respiration.

Question 5.
Why Diazene Green solution is added to the glucose solution in anaerobic respiration experiment?
Answer:
Diazene Green solution is added to the glucose solution in anaerobic respiration experiment to check the presence of oxygen in glucose solution.

Question 6.
Name the food material on which trypsin acts and name the end products.
Answer:

• protein
• end products – peptones.

Question 7.
Identify the figure.
Answer:

Aerial roots in Mangrove plants.

Question 8.
“Respiration is the energy releasing process.” Write your opinion on this statement.
Answer:
The given statement is absolutely correct. We respire to use the oxygen to oxidise our food and release energy. This is similar like burning but a slower process. With the help of respiratory enzymes, energy released can he stored in the form of ATP for later use.

Question 9.
Can we say that combustion and respiration are almost same actions. What evidences do you have for this ?
Answer:

• In both these processes sugar is converted to carbon dioxide and water.
• Both these processes require oxygen
• Both combustion and respiration releases energy.

Question 10.
What is the role of epiglottis in respiration and swallowing food ?
Answer:
The epiglottis is a flexible flap at the superior end of the pharynx in the throat. Epiglottis acts as a lid over glottis and prevents food from entering into larynx. Air from pharynx enters the larynx while food enters into oesophagus.

Question 11.
What is the pathway of air from nostril to alveolus ? mm
Answer:
Nostrils  Nasal cavity  Pharynx  Larynx  Trachea  Bronchus  Bronchioles  Alveolus  Blood.

Question 12.
What is respiration ?
Answer:
Respiration is the process by which food is broken down for release of energy.

Question 13.
What does the respiration mean ?
Answer:
It means ‘to breathe’ in Latin.

Question 14.
Who did comprehensive work on properties of gases, their exchange and respiration ?
Answer:
Lavoisier and Priestly.

Question 15.
What was the gas liberated on heating powdered charcoal in a hell jar 2
Answer:
It was fixed air. In those days carbon dioxide was known as fixed air.

Question 16.
What was produced by combustion according to Lavoisier ?
Answer:
Carbon dioxide.

Question 17.
What is vitiated air ?
Answer:
A term used then to show air from which the component needed for burning had been removed.

Question 18.
Which gas, according to Lavoisier, is respirable air ?
Answer:
Oxygen.

Question 19.
Who was the renowned chemist ? Who wrote a textbook of Human Physiology ?
Answer:
John Daper.

Question 20.
What happens when air passes through nasal cavities ?
Answer:

• Air is filtered in nasal cavity’ by mucus lining and the hairs growing from its sides remove some of the tiny particles of dirt in the air.
• The temperature of the air is brought close to that of the body.

Question 21.
What is the function of epiglottis ?
Answer:
Epiglottis controls the movement of air and food towards their respective passages.

Question 22.
Where does gaseous exchange take place?
Answer:
Gaseous exchange takes place in tiny air sacs of lung called Alveoli.

Question 23.
What is breathing?
Answer:

• Breathing is the process of inhaling and exhaling.
• The mechanism by which organisms obtain oxygen from the environment and release carbon dioxide is called breathing.

Question 24.
What is inspiration or inhalation?
Answer:
Entry of air into lungs from outside is inspiration.

Question 25.
What is expiration or exhalation?
Answer:
It is the pushing out air from lungs to outside.

Question 26.
What are pleura?
Answer:
Pleura are the two membranes that protect lungs from injury.

Question 27.
What is cellular respiration?
Answer:
Oxidation of glucose or fatty acids takes place In the cells and releasing energy. Hence this process is known as cellular respiration.

Question 28.
What is aerobic respiration?
Answer:
Oxidation of glucose in presence of oxygen is called aerobic respiration.

Question 29.
What is anaerobic respiration?
Answer:
Respiration in absence of oxygen is called anaerobic respiration.

Question 30.
Where does aerobic respiration occur in eukaryotic cells?
Answer:
Cytoplasm and Mitochondria.

Question 31.
What is Glycolysis?
Answer:
It is the breakdown of glucose molecule into two molecules of 3 carbon compound called pyruvic acid or pyruvate releasing energy.

Question 32.
What is the fate of pyruvate in the absence of oxygen in plants?
Answer:
In the absence of oxygen pyruvate will be converted to ethanol, CO2 releasing energy in plants.

Question 33.
What is the fate of pyruvate in the absence of oxygen in animals?
Answer:
In the absence of oxygen pyruvate will be converted to lactic acid releasing small amount of energy.

Question 34.
In aerobic respiration pyruvate is converted into?
Answer:
If oxygen is available pyruvate is oxidized to CO2 and water releasing large amount of energy.

Question 35.
What is the main reason for feeling pain in muscles after strenuous exercise?
Answer:
Due to the anaerobic respiration in muscles large amounts of lactic acid is accumulated and this results in muscular pains.

Question 36.
What is fermentation?
Answer:
In the absence of oxygen, yeast cells convert pyruvic acid to ethanol. This process is called fermentation.

Question 37.
What is the method used to separate ethanol from the yeast glucose mixture in anaerobic respiration?
Answer:
By Fractional distillation method.

Question 38.
What is combustion?
Answer:
Combustion is a process in which heat is released when organic molecules (sugar) are burnt, CO2 and H2O are released.

Question 39.
In which organisms exchange of gases takes place through diffusion?
Answer:
Amoeba, hydra and planarians.

Question 40.
In tracheal respiratory system which carry air directly to the cells in the tissues?
Answer:
Trachioles, the fine branches of trachea.

Question 41.
In fishes what are the respiratory organs?
Answer:
Gills or bronchiae.

Question 42.
What is cutaneous respiration?
Answer:
If the respiration occurs through skin, it is known as cutaneous respiration. e.g: Leech, Earthworm and Frog.

Question 43.
What are the other areas on the plant body through which gaseous exchange take place?
Answer:
It is through the surface of roots, lenticels on stem.

Question 44.
What is the full form of ATP ? How is it formed?
Answer:

• ATP stands for Adenosine triphosphate.
• The energy released during respiration process is used to make an ATP molecule from Adenosine diphosphate (ADP) and inorganic phosphate (P).

Question 45.
Whatis the use of ATP?
Answer:

• ATP is the energy currency for most cellular process.
• ATP is used to supply energy in the cells for carrying all the metabolic processes.

Question 46.
What are the factors that control respiration?
Answer:
Oxygen and temperature are the two important factors that control the process of respiration.

Question 47.
What are the substances that are used for the production of energy in all living organisms?
Answer:
Glucose and fatty acids are used for the production of energy.

Question 48.
How many types of respiration are present? What are they?
Answer:
There are two types of respiration. They are

• Aerobic respiration
• Anaerobic respiration.

Question 49.
Where is energy stored in ATP?
Answer:
Energy is stored in the terminal phosphate bond in ATP which is having three phosphates attached to a molecule of Adenosine.

Question 50.
What are the power house of the cell?
Answer:
Mitochondria are the power house of the cell.

Question 51.
What is the main difference between respiration and combustion?
Answer:
In respiration several intermediates are produced and in combustion there are no such intermediates are produced.

Question 52.
What are the end products of aerobic respiration?
Answer:
CO2 and H2O are the end products of aerobic respiration.

Question 53.
What is the equation that represents respiration?
Answer:
C6H12O6 + 6O2 → 6 CO2 + 6H2O + 686 KCal.

Question 54.
What are the sites of cellular respiration?
Answer:
Mitochondria are the sites of cellular respiration.

Question 55.
What are cristae in mitochondria?
Answer:
The inner membrane of mitochondria is thrown into several folds called cristae.

Question 56.
What is the net gain of ATP molecules in Glycolysis?
Answer:

• Four ATP molecules are produced when one molecule of glucose is converted to two molecules of pyruvate but two are consumed.
• The remaining two ATP molecules are net gain in glycolysis.

Question 57.
What are the number of ATP molecules produced when one glucose molecule is completely oxidised?
Answer:
A net gain of 38 ATP molecules are formed from the total oxidation of one glucose molecule.

Question 58.
What are the three stages present in complete oxidation of glucose molecule?
Answer:

• Glycolysis
• Krebs cycle
• Electron transport.

Question 59.
Why does oxidation of fatty acids give more energy?
Answer:
Oxidation of fatty acids gives more energy due to the presence of more carbon atoms in them.

Question 60.
What is meant by aquatic animals and terrestrial animals?
Answer:
Animals that live on land are known as terrestrial animals and animals that live in water are called aquatic animals.

Question 61.
Why is the rate of breathing in aquatic organisms much faster than terrestrial organisms?
Answer:
The amount of dissolved oxygen in water is low as compared to the amount of oxygen in air, therefore the rate of breathing in aquatic animals is much faster than in terrestrial animais.

Question 62.
Which part of roots is involved in the exchange of respiratory gases?
Answer:
The respiration in roots occurs by the diffusion of respiratory gases through root hairs.

Question 63.
Name the areas in a woody stem through which respiratory exchange of gases takes place.
Answer:
In woody stems, the bark (outer covering of stem) has lenticels for gaseous exchange.

Question 64.
Out of photosynthesis and respiration in plants which process occurs all the time and only at daytime?
Answer:
Respiration occurs all the time and photosynthesis occurs only at daytime.

Question 65.
The trachea divides into two tubes at its lower end What is the name of these tubes?
Answer:
Bronchus.

Question 66.
What is the average breathing rate in an adult man at rest?
Answer:
The average breathing rate in an adult man at rest is about 15 to 18 times per minute.

Question 67.
Why is trachea prevented from collapsing?
Answer:
The wails of the trachea are supported by several ‘C’ shaped cartillagenous rings.
They prevent the trachea from collapsing and closing.

Question 68.
What has raised the percentage of carbon dioxide in exhaled air?
Answer:
During oxidation of glucose carbon dioxide is produced as waste product. Hence the concentration of carbon dioxide increases in exhaled air.

Question 69.
What are the reasons for the animals to develop different types of respiratory organs?
Answer:
Body size, availability of water, habitat in which they live and the type of circulatory system are some of the reasons for the animals to develop different types of respiratory organs.

Question 70.
Why do fishes die when taken out of water?
Answer:
This is because fishes do not have lungs to utilise the oxygen of air for breathing and respiration. They have gills which can extract and dissolve oxygen from water for survival.

Question 71.
What would be the consequences of deficiency of haemoglobin in our bodies?
Answer:
Deficiency of haemoglobin in blood can affect the oxygen supplying capacity of blood in body cells. It can also lead to a disease called Anaemia.

Question 72.
Which gas did you think is Lavoisler talking about when he says chalky acid gas?
Answer:
It is carbon dioxide.

Question 73.
What is the composition of inhaled air?
Answer:
Inhaled air contains 21% of oxygen, 0.04% carbon dioxide and 79% of nitrogen.

Question 74.
What is the composition of exhaled air?
Answer:
Exhaled air contains 16% of oxygen, 4% of carbon dioxide and 79% of nitrogen.

Question 75.
Why does the amount of nitrogen not vary between exhaled and inhaled air?
Answer:
Because nitrogen has no role to play in respiration.

Question 76.
In which kind of respiration more energy is released?
Answer:
In aerobic respiration more energy around (686 KCal) is released than in anaerobic respiration (58 KCal).

Question 77.
Which gases are exchanged in your lungs?
Answer:
Oxygen and carbon dioxide.

Question 78.
The bark of woody plants is dead but the inner layers inside the bark are living.
OR
How do they get oxygen and release carbon dioxide?
Answer:
Through lenticels.

Question 79.
What are lenticels?
Answer:
Lenticels are portions of the periderm (bark) with numerous intercellular spaces. Their purpose is to allow gas exchange through the compactly arranged cork cells of the bark, which otherwise presents an impermeable barrier to the passage of water and gases.

Question 80.
How does diaphragm help in inhalation?
Answer:
It flattens during inhalation, thus increasing the volume of the thoracic cavity.

Question 81.
Name the type of respiration in which the end products are
a. C2H5OH and CO2
b. CO2 and H2O
c. Lactic acid.
Answer:
a. Anaerobic respiration in yeast
b. Aerobic respiration
c. Anaerobic respiration in muscles.

Question 82.
“If there were no algae, there would be no fish in the sea” Comment.
Answer:
Algae produce oxygen as a result of photosynthesis. This oxygen is utilised by the fishes in the sea for carrying out respiration. If there were no algae, no oxygen would have been produced. Thus fishes might have died.

2 Marks Questions

Question I.
What happens if there is no epiglottis in human beings?
Answer:

• Food may enters into the larynx.
• Food may enters into the lungs leading to the death.
• May not speak properly.
• Entry of food and air may not he regulated properly.

Question 2.
Write two chemicals and two materials required to conduct the experiments “Heat and Carbon dioxide are evolved during anaerobic respiration”.
Answer:
Materials required : Thermosflask, splitted corks, thermometer, wash bottle, glass tubes.
Chemicals required : Liquid paraffin, glucose solution, bicarbonate solution, Janus green B and Yeast cells.

Question 3.
Observe the below diagram.
A. This picture is related to which biosystem?
B. Write the names of the parts of A, B.
C. To which system they are linked with?
D. Which process is happening here?
What happens as a result of it?
Answer:

A. Respiratory system.
B. A – alveolus; B – blood capillary network
C. Respiratory system; circulatory system.
D. Gaseous exchange between alveolus of lungs and blood capillaries. Due to this the CO2 present in blood capillaries enter alveolus and oxygen present in alveolus enter blood capillaries.

Question 4.
A person reached a specific distance once on foot and once by running. In which situation his legs pain ? Why?
Answer:

• When a person rules to reach a specific distance gets pain in his legs.
• This is due to the production of lactic acid in the muscles.
• The sugar ¡n the working muscles when a person runs was being changed to lactic acid.
• Accumulation of lactic acid results pain in leg muscles.

Question 5.
What is the advantage of the wet and warm passage of air from the nostrils to capillaries?
Answer:
The foist surface of the lining of the nasal cavity and the hair growing from it sides, remove some of the tiny particles of dirt in the air. In addition as the inhaled air passes through the nasal cavity, its temperature is brought close that of the body and it takes up water vapour so that it becomes more moist than before. Warming and moistening is goes on in the pharynx and also throughout the respiratory tract.

Question 4.
In the experiment of anaerobic respiration with yeast
i. Why was liquid paraffin poured on glucose?
ii. What did you understood about anaerobic respiration?
Answer:
i. The supply of oxygen from the air can be cut off by pouring liquid paraffin on glucose.
ii. Anaerobic respiration takes place in the absence of oxygen. In this glucose molecule is incompletely oxidised. The end products of anaerobic respiration are ethyl alcohol or lactic acid and CO2.

During anaerobic respiration small amount of energy is liberated (2ATP). Anaerobic respiration occurs in many anaerobic bacteria and human triuscies cells. The anaerobic respiration can he represented as:
C6H12O6 → 2C2H5OH + 2CO6+ 56 K.Cal.

Question 5.
See the below table. Write what you know from it.
Answer:

 Gas % in inhaled air % of exhaled air Oxygen 21 16 Carbon dioxide 0.04 4 Nitrogen 79 79

Answer:

• The inhaled air consists of 21% of oxygen whereas the exhaled air contains 16% of oxygen only. ‘[his is due to utlilisation of oxygen during cellular respiration in the body. Hence the difference occurs.
• inhaled air contains 0.04% of carbendiuxide whereas exhaled air contains 4% of carbondioxide. The concentration of CO2 is increased a lot due to the release of CO2 during cellular respiration in the body.
• Both inhale and exhale air contains 79% of nitrogen because nitregen has no role to play in cellular respiration.

Question 6.
How does the respiration in amoeba and hydra occur through diffusion? What are the similarities in respiration of amoeba and hydra?
Answer:

• Amoeba and hydra are aquatic organisms.
• Respiration in them occurs through diffusion.
• As oxygen is used by these organisms in respiration its concentration is reduced in cytoplasm and hence oxygen diffuses into cytoplasm from surrounding water.
• Due to respiration CO2 is continuously produced, its concentration increases in the cytoplasm, hence it diffuses into surrounding water.

Question 7.
What are different ways in which glucose is oxidised to provide energy in various organisms?
Answer:
Breaking down of glucose involves two processes. In the first step, it is broken into three carbon molecules called pyruvate. The pyruvate is further broken down into energy in following different ways in various organisms.

• Aerobic respiration : In this case pyruvate is broken town into water and carbon dioxide along with release of energy. It commonly occurs in mitochondria of cells.
• Anaerobic respiration in yeast : In yeast cells during fermentation pyruvate is converted into ethanol and CO2 in the absence of O2
• Anaeorbic respiration in muscles: Due to lack of oxygen. eg. during vigorous running or exercise, in human muscles, pyruvate is converted to lactic acid.

Question 8.
How does respiration in plants differ from that iii animals?
Answer:

• In plants all parts like root, stern, leaves, etc., perform respiration individually, while in animals either the general body surface or specific organs like skin, gills, lungs, etc., are involved in respiration.
• The rate of respiration is much slower in plants than in animals. Unlike animals there is little transport of gases from one part of the plant to another.

Question 9.
Write about respiration in mangroves that grow in marshy lands.
Answer:

• Mangroves grows near the marshy places respire through aerial roots or respiratory roots.
• The root hairs exchange the gases from their surface.
• They obtain oxygen from the airspaces present between the soil particles.
• The plants grows in marshy places are adapted to develop aerial roots above the soil surface which helps in gaseous exchange.

4 Marks Questions

Question 1.
Explain different steps In respiration in human beings.
Answer:
Different steps in respiration in human beings.

Breathing : Air movement into and out of lungs.
Gaseous exchange at lungs level: Exchange of gases between alveoli and blood.
Gas transport by blood : Transport of oxygen from blood capillaries of alveoli to
blood cells and return of carbon dioxide.
Gaseous exchange at tissue level : Exchanging of oxygen from blood into the cells and
carbon dioxide from cells into the blood.
Cellular respiration: Using oxygen in cell processes to produce carbon dioxide and
water, releasing energy to be used for life processes.

Question 2.

observe the above diagram and answer the following questions:

i. What does the above setting (diagram) indicate?
Answer:
The above setting (diagram) indicate to prove that carbon dioxide and heat are liberated during anaerobic respiration by yeast cell.

ii. Why boiled and cooled glucose is covered with paraffin?
Answer:
To prevent supply of air boiled arid cooled glucose is covered with paraffin.

iii. What is the use of adding diazime green to glucose solution ? What change you notice in glucose solution?
Answer:
Diazine green is added to glucose solution to know whether oxygen is present or not in glucose solution. When the availability of oxygen is less the diazine green changes to pink colour.

iv. Why lime water is used lu this experiment?
Answer:
To know whether carbon dioxide is released or not in this experiment lime water is used. Carbon dioxide changes lime water to milky white.

v. Why bulb of thermometer is dipped in the glucose water?
Answer:
To know the rise in temperature of glucose solution when heated, the bulb of thermometer is dipped in the glucose water.

Question 3.
Study the graph and answer the following questions:
Graph showing effects of vigorous excercise on the concentration of lactic acid in blood.
on the concentration of lactic acid in blood.
i. What was the concentration of lactic acid in blood to start with?
ii. What was the greatest concentration of lactic acid reached during the experiment?
iii. What is the concentration of lactic acid after 25 minutes of exercise?
iv. What is the relationship between lactic acid and muscle pain?
Answer:

i. 20mg/cm3
ii. 20 minutes (Or) at ‘B” point.
iii. 101 mg/cm3
iv. If concentration of lactic acid increases muscle pains also increases.

Question 4.
Explain with the help of a flow chart, the pathway of air in humans.
Answer:

Question 5.
Observe the following:

Write the answers to the following questions:

i. How many Pyruvic acid molecules form from one Glucose?
Answer:
2 Pyruvic Acid molecules.

ii. What conditions influences Pyruvic acid to participate in Aerobic and Anaerobic respiration?
Answer:
Presence of oxygen

iii. In which we get more energy in both Aerobic and Anaerobic respiration?
Answer:
Aerobic respiration

iv. The chemical that is formed in human muscles during Anaerobic respiration.
Answer:
Lactic Acid

I. Conceptual Understanding

Question 1.
Describe the structure of mitochondria with the help of a diagram.
OR
Which cell organelle is called energy currency or power house of cell?
OR
What do you know about its construction?
Answer:
Structure of mitochondria:

• Mitochondria is known as energy currency or powerhouse of cell.
• Mitochondria can be seen with a special microscope called electron microscope.
• Mitochondria are sac-like structures present in the cytoplasm of the cells.
• They may be of various shapes thread-like, spherical.
• Mitochondria have two compartments – an two compartment and zin outer compartment. The substance in the inner compartment is called matrix.
• The matrix is surrounded by a membrane called inner membrane of mitochondria.
• The inner membrane is thrown into several folds called cristae. The cristae extended into the matrix.
• The space between the folds is continuous with the outer compartment.
• The outer compartment is surrounded by another membrane – the outer membrane. The outer membrane is smooth and has no projections.
• The inner membrane, the matrix and the elementary particles in the mitochondria have large number of enzymes and other required proteins for the respiration and energy production.

Question 2.
Why the exchange of gases happens only in alveoli, though arteries are present in pharynx, trachea and bronchus?
Answer:
Alveoli have several adaptations to maximize the efficiency of gas exchange. They fold to provide a wider surface area for gas exchange to take place and they are ventilated to remove carbon dioxide and to replenish oxygen levels in the alveolar air.

This maintains maximum concentration gradient which refers to the difference in the concentration of a chemical across a membrane, between the air in the alveoli and blood. The alveoli have thin walls that are one cell thick to make the exchange surface extremely thin.

Question 3.
Describe how oxygen enters the blood in lungs with the help of block diagram?
OR
How gaseous exchange occurs in lungs?
Answer:

• Gaseous exchange takes place within the lungs by diffusion from the alveoli to blood capillaries and vice versa. Alveoli in lungs are numerous and only one cell thick.
• Alveoli are surrounded by capillaries that are also one cell thick
• Blood, dark red in colour flows from the heart through these capillaries and collects oxygen from the alveoli. At the same time, carbon dioxide passes out of the capillaries and into the alveoli.
• When we breathe out, we get rid of carbon dioxide.
• The bright red, oxygen rich blood is returned to the heart and pumped out to all parts of the body.

Question 4.
What is the role of diaphragm and ribs in respiration ? Are both active in man and woman ?
OR
Is respiration possible without diaphragm and ribs in human? Explain.
Answer:

• Diaphragm is a muscular dome shaped tissue present at the floor of the chest cavity separating abdomen from respiratory system.
• Diaphragm expands downwards into the abdomen thus increasing chest cavity. This allows the lungs to expand as we inhale.
• As the diaphragm contracts upwards thus decreasing the chest cavity, it allows the air to expel from the lungs.
• The ribs protect the lungs and expand as we inhale to facilitate space for the lungs to expand. The ribs then contract expelling the air in the lungs.
• The intercostal muscles present between the ribs help in contraction and relaxation of ribs.
• In man, diaphragm plays a major role in the respiration, while in woman, the ribs play a major role.

Question 5.
Explain the process of transportation of gases through the blood.
Answer:
1. The relative amount of gases and their combining capacity with haemoglobin and other substances in blood determine their transport via blood in the body.

2. When oxygen present in the air is within normal limits (around 21%) then almost all of it is carried in the blood by binding to haemoglobin, a protein present in the red blood cells.

3. As oxygen is diffused in the blood, it rapidly combines with the haemoglobin to form oxyhaemoglobin.

4. Not only haemoglobin can combine with oxygen, but the reverse can also happen to yield a molecule of haemoglobin and oxygen.

5. Carbon dioxide is usually transported as bicarbonate, while some amount of it combines with haemoglobin and rest is dissolved in blood plasma.
Hb + 4O2 → Hb(O2)4 (in lungs)
Hb(O2)4 → Hb + 4O2 (in tissues)

Question 6.
What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.
Answer:

• Glucose is the most commonly used sugar for deriving energy in plants, animals and in micro-organisms.
• In all these organisms glucose is oxidised in two stages.
• The first stage is known as Glycolysis. It occurs in cytoplasm.
• During glycolysis glucose is converted to two molecules of pyruvic acid.
• In the second stage, if oxygen is available pyruvic acid is converted to CO2 and water, large amount of energy is released. This is known as aerobic respiration. In most of the plant and animal cells aerobic respiration occurs.
• If oxygen is inadequate or not available, pyruvic acid is converted into ethanol and carbon dioxide. This is anaerobic respiration. taking place in yeast cells that is called fermentation.
• If oxygen is not available in muscle cells, the pyruvic acid is converted into lactic acid.

Question 7.
Write a brief note on respiration in plants.
Answer:

• In most plants exchange of gases takes place through stomata.
• There are other areas on the plant body as well, through which gaseous exchange takes place like surface of roots, lenticels on stem, etc.

• Some plants have specialized structures like, breathing roots of mangrove plants as well as the tissue in orchids.
• Breathing roots and tissue in orchids help plants to take oxygen to produce energy and carbon dioxide is released.
• Inside the plants stomatal openings lead to a series of spaces between the cells which form a continuous network all over the plant.
• The whole system works by diffusion.
• As the oxygen is used up by the cells a gradient develops between the cells and the air in the spaces and similarly between the air spaces and the air outside stomata and lenticels, so oxygen passes in.
• In the same way, as more carbon dioxide is given out by the cells, a gradient occurs in the reverse direction and it passes out.

Question 8.
Write the adaptations seen in plants living in water logged conditions.
Answer:

• Most plants can aerate their roots by taking in the oxygen through lenticels or through the surface of their root hairs.
• But plants which have their roots in very wet places, are unable to do this.
• They are adapted to these water logged conditions by having much larger air spaces which connect the stems with the roots, making diffusion from the upper parts much more efficient.
• The problem of air transport is more difficult for trees and many not survive with their roots permanently in water.
• An exception is the mangrove tree of the tropics which sends up aerial roots above the surface and takes in oxygen that way.

Question 9.
Write a brief note on tracheal respiration in insects.
Answer:

• In insects blood has no haemoglobin and is white in colour. Hence it cannot carry oxygen.
• For respiration insects adopt a special system called tracheal system.
• This system consists of a series of tubes called trachea.
• These trachea open out through small apertures called spiracles on either side of the body.
• All tracheal tubes of each side join and form a longitudinal tracheal trunk.
• Trachea divide into a number of branches called tracheoles which carry air directly to the tissues.
• As the air moves in and out of the trachea, oxygen present in the air diffuses into the cells and CO2 diffuses into the air from the cells.

Question 10.
Write about the mechanism of respiration in human beings.
Answer:

• Respiration in man occurs in two stages. They are inspiration and expiration.
• During inspiration air from outside enters into the lungs by increasing the thoracic cavity.
• lncrease in the thoracic cavity is made by pulling the diaphragm down and pushing the ribs forward.
• As the air pressure in the lungs is reduced, air from outside enters the lungs through external nostrils, nasal cavities, pharynx, epiglottis, larynx, trachea, bronchi and bronchioles and finally reach the alveoli where exchange of gases takes place.
• During expiration the diaphragm and ribs come back to original positions.
• This reduces the volume of thoracic cavity.
• So the volume of lungs is decreased and air under lressure comes out of the lungs.

Question 11.
Explain the evolutionary changes in energy releasing system.
Answer:

• Exchange of gases is a common life process in all living organisms, but it is not same in all.
• Single celled organisms amoeba or multicellular organisms like hydra and planarians obtain oxygen and expel carbon dioxide directly from the body by the process of diffusion.
• In multicellular animals special organs are evolved.
• Animals either terrestrial or aquatic adopted different types of respiration and different types of respiratory organs mostly due to the habitat in which they live.
• Body size, availability of water and the type of circulatory system are some of the reasons for the animals to develop different types of respiratory organs.
• In insects tracheal respiratory system is present in which small branches of trachea called tracheoles carry air directly to the cells in the tissues.
• In fishes gills are utilised for the exchanges of gases. Blood is supplied to gills through capillaries which have thin walls for exchange of gases. This is called bronchial respiration.
• Respiration through skin is called cutaneous respiration.
• This type of respiration is seen in earthworm and leeches.
• Frog, an amphibian can respire through cutaneous pulmonary processes.
• Most of the higher animals respire with the help of lungs. This type of respiration is known as pulmonary respiration.

Question 12.
Describe the structure of human lungs with the help of a diagram.
Answer:

• A pair of lungs is present in the chest cavity one on either side of the heart.
• Lungs are spongy and elastic and are enclosed by two membranes called pleura.
• Space between the two membranes of Pleura is filled with fluid. Pleura protects the lungs from injury.
• Right lung is larger than the left lung.
• Right lung is made of three lobes while the left lung has only two lobes.
• Lung has several thousands of alveoli which are supplied with blood capillaries.
• Pulmonary artery brings deoxygenated blood from heart to lungs.
• After entering the lung. this artery divides into several arterioles and capillaries and supplies deoxygenated blood to alveoli.
• Gas exchange occurs in the alveoli.
• Oxygenated blood is carried from the lung to heart by the pulmonary vein.

III. Experimentation And Field Investigation

Question 1.
What are the experiments carried out by Lavoisier to understand the property of gases ?
Answer:

• In his early experiments Lavoisier thought that the gas liberated on heating powdered charcoal in a bell jar kept over water in a trough was like fixed air i.e., carbon dioxide.
• The next series of experiments deals with the combustion of phosphorus in a bell jar. From this he showed that whatever it was in the atmospheric air which combined with the phosphorus was not water vapour.
• This was respirable air, a component of air that also helped in burning.
• The air that we breathe out precipitated lime water while that after heating metal did not.
• From this he concluded that there were two processes involved in respiration.
• Lavoisier carried out another experiment by which he showed that about one-sixth of the volume of vitiated air’ consists of chalky acid gas (fixed air).
• Either eminently respirable air is changed in the lungs to chalky acid air; or an exchange takes place, the eminently respirable air being absorbed, and an almost equal volume of chalky acid air being given up to the air from the lungs.
• Lavoisier had to admit that there were strong grounds for believing that eminently respirable air did combine with the blood to produce the red colour.

Question 2.
Study the graph given below and analyse the reasons for accumulation of lactic acid in blood after strenuous exercise.
Answer:

Answer:

• The graph shows the analysis of blood of a person during and after exercise.
• The athlete taking part in the experiment had to stay still where the apparatus was.
• He pedaled a stationary bicycle, or ran on a tread mill.
• Some results are shown in the graph.
• Vigorous exercise lasted for nine minutes (shown by the bar at the base of the diagram) and regular blood samples were taken and analysed.
• One particular compound in the blood, lactic acid, was found to vary greatly in its concentration as we see from the graph.

IV. Information Skills and Projects

Question 1.
Observe following table and answer the questions given below.

 Gas % in inhaled air % in exhaled air Oxygen 21 16 Carbon dioxide 0.03 4.4 Nitrogen 78 78

A. Why does the amount of oxygen vary between exhaled and inhaled air?
Answer:
Gaseous exchange takes place in alveoli of lungs where oxygen is taken in, hence exhaled air contain 16% oxygen.

B. Why does exhaled air contain more carbon dioxide?
Answer:
In lungs gaseous exchange takes place in alveoli, CO2 present in blood diffuses into alveoli. The collected CO2 comes out as exhaled air.

C. Why there is no change in Nitrogen percentage in exhaled and inhaled air?
Answer:
Nitrogen is not present in our body. Hence there is no change in nitrogen.

V. Communication Through Drawing, Model Making

Question 1.
Draw a neat labelled diagram of power house of a cell. What is the function of inner membrane?
Answer:

Question 2.
Label the parts for given diagram.
Answer:

1. Larynx
2. Trachea
3. Right Lung
4. Brochus
5. Bronchioles

Question 3.
A student conducted an experiment in which he proved CO2 evolved in respiration of sprouts. Draw diagram of apparatus arrangement and label parts.
Answer:

VI. Appreciation And Aesthetic Sense, Values

Question 1.
In human respiratory system different stages are there begining with nostril to gaseous exchange between blood and cell. Which of these stages do you think amazing? Why do you think so?
Answer:

• Human body consists of trillions of trillions cells, each cell in human body gets oxygen for respiration which ultimately releases energy in the form of ATR
• Most amazing thing is all the huge number of cells getting oxygen for respiration and this oxygen enter in cells through diffusion.

VII. Application to Daily life,Concern to Biodiversity

Question 1.
After learning this lesson what precautions will you lake to protect your lungs?
Answer:

• I would try to avoid most pollutant atmosphere.
• Whenever exposed to air pollutants I cover the nose and mouth with mask or cloth.
• I like to keep our surroundings parthenium’ free to avoid asthma.
• I don’t smoke and I keep away from smokers.
• I practice pranayarna to strenthen lung capacity and concentration.

## TS 10th Class Biology Study Material 10th Lesson Natural Resources

Telangana SCERT 10th Class Biology Study Material Telangana 10th Lesson Natural Resources Textbook Questions and Answers.

## TS 10th Class Biology 10th Lesson Questions and Answers Telangana – Natural Resources

Question 1.
The BP statistical Review of World Energy in June measured total global oil at 188.8 million tonnes, from proved oil resources at the end of 2010. This is only enough for oil to last for the next 46.2 years. What measures should be taken to conserve oil? What will happen if we do not conserve it.
Answer:
Fossil fuels were produced from the remains of ancient plants and animals. They include coal, petroleum (oil) and natural gas. Apart from its use in vehicles, many of the products we use today are made from petroleum. We need to conserve fossil fuels so we don’t run out of them.

• Everyone can help conserve fossil fuels by using them carefully.
• Turn of lights and electronics when you are not using them.
• Purchase energy – efficient appliances. Prefer ‘ISI’ mark utensils / appliances.
• Walk, ride a bicycle and use public transportation whenever possible.
• It is better to prefer public transport system like bus or train instead of travel in personal vehicles
• Going together by using one vehicle of work place.

It is estimated that the available supply of fossil fuels their supply gets exhausted in another 42- years. in such a case, all the industries and transport vehicles, which use fuels cannot be run once the fuel supply is exhausted. Hence, indiscriminate use of these fuels should be avoided.

Question 2.
Here is a news strip, read it carefully and answer the following questions Villagers oppose sand mining project Santhabommali (Srikakularn): People of more than 20 villages in two mandals of Srikakulam have raised a banner of revolt against the proposed beach sand mining project by a private company and threatened to intensify their agitation if the government does not cancel the project. The sand mining is being taken up to extract rich minerals from the
area. The villages are located around the forest belt were mining was initiated.
i. Do you think the villagers are doing a right thing to agitate? Why?
ii. What resources are the villagers trying to save by their agitation?
iii. Will the villagers be benefitted by the rich minerals extracted from sand?
iv. Why does the private company want to carry out mining in the beach area?
v. What is the role of the government in this aspect?
vi. How will mining in that piece of land affect people of the area?
Answer:
Village oppose sand mining project Santhabomn all (Srikakulam): People of more than 20 villages in two mandals of Srikakulam have raised a banner of revolt against the proposed beach sand mining project by a private company and threatened to intensify their agitation if the government does not cancel the project. The sand mining is being taken up to extract rich minerals from the area. The villages are located around the forest belt were mining was initiated.

i. Do you think the villagers are doing a right thing to agitate ? Why?
Answer:
Yes, the villagers are doing a right thing to agitate. Because beach sand mining leads to certain problems such as:

• Destruction of natural beaches and the ecosýstemS.
• Habitat loss for globally important species such as turtles, shore birds, etc.
• Destruction of nearshore marine ecosystems.
• Increased shoreline erosion rates.
• Reduced protection from storms, tsunamis and wave events.
• Economic losses through tourist abandonment
• Loss of coastal aesthetics and
• Increased saline water intrusion.

The threats posed by sand mining are made even more critical given the prospect of a significant rise in global sea level over the coming decades.

ii. What resources are the villagers trying to save by their agitation?
Answer:
By agitating the villagers can save valuable mineral called Titanium / Zirconium found exclusively in costal belt spread from Nellore to Srikakulam district covering a distance of about 972 Km.

iii. Will the villagers be benefitted by the rich minerals extracted from sand?
Answer:
No, the villagers will not be benefited by the rich minerals extracted from sand.

iv. Why does the private company want to carry out mining in the beach area?
Answer:
Private company wants to carry out mining in the beach area for their benefits, they want to earn money.

v. What is the role of the government in this aspect?
Answer:
The government has to take action against the private people if they start mining, which harm people or if government give permission and control the process where it should not effect the people.

vi. How will mining in that piece of land affect people of the area?
Answer:
Mining causes air pollution which leads to the diseases of respiratory system like lung cancer, Asthma, etc

Question 3.
What is sustainable development? How is it useful in natural resource management?
Answer:
When we use the environment in ways that ensure we have resources for the future, it is called sustainable development. Development and conservation can co-exist in harmony. The earth’s natural resources include air, water, soil, minerals, fuels, plants and animals. AH the things we need to survive such as food, water, air and shelter.

Conservation is the practice of caring for these resources to all living things can benefit from them now and in the future. The development meet the needs of the present without compromising the ability of future generation to meet their own needs.

Question 4.
Write a detailed note on management of a natural resource.
Answer:
The interest in conservation is not a sentimental one but the discovery of a truth well known to our ancient stages. The Indian tradition teaches us that all forms of life-human, animal and plant – are so closely inter-linked, that disturbance in one gives riseto imbalance in another (By Srimathi Indira Gandhi, while launching the world conservation strategy in India on 6th March 1980.)

Small steps could become great efforts at conservation. Protection of the environment:

• Soil, water, air, animals, birds, plants and trees are not anybody’s property.
• That is the collective property bestowed on us by nature. We use the natural resources to produce many things. Some of them are our own, while others are public property.
• Village – tanks, ponds, vegetable markets, bus stands, railway stations, temples, schools and colleges are public property and are used by aH.
• Everyone should join hands to protect them. It’s not a single individual’s jobs.
• Only when we collectively take up the tasks like growing trees besides roads, providing drainage or keeping the surroundings of the public tap in our colony clean we can be successfully.
• This is a collective responsibility. – Protection of the natural resources is possible only if all of us join hands together.

Question 5.
Suggest some ways of reusing a resource in your locality?
Answer:

• If a fine soft coarse of blanket is to cover open springs to save wear of springs on sheets and mattress.
• Bottle cap as dent patcher in a wooden table. Put a metal bottle cap over the dent with the fluted edge facing upward towards the table, press the centre of the capightly with the tip of a hot iron.
• Buttons : If you have only two attractive buttons make them into a pair of earrings. If you have 4 attractive buttons make them into a pair of cufflinks, chain stitch
• Candle stubs: For corking bottles when you lost the cork soften a candle stub that it fits the neck of the bottle.
A candle stub also make excellent fire starters. Candle stub can be saved and melted together and make into new candles.
• The used bangles which are thrown a side can be used as a pen stand by sticking them one on the other.
• Paper, a product of many trees can be put reuse after proper use. If it is done properly, definitely their practice would save many plants from extinctions. Thus reduce the effect of CO2 on the earth.

Question 6.
Why should we conserve forests and wild life?
Answer:
Wildlife and forests should be conserve for the following reasons.

• Wildlife and forests are the measures of Biodiversity of a particular legion. By conserving the wildlife and forests, we are ensuring that all diverse species in an area survive, breed and flourish.
• Conservation of forests and wildlife is vital for the ecological stability of particular area.
• Forests are the habilitate for the wildlife and they are an important constitute of the various food chains and food webs. Forests are needed for smooth functioning of Biochemical cycles.
• Forests are necessary for the formation of human and for maintaining soil fertility.
• Forest pure air protect the earth from green house effect by removing carbon dioxide and converting it into oxygen. Thus forests protecting us from harmfully effects of global warming.
• Many fruits, medicines, dyes, sandle wood and bamboo is obtained from forest by local people.
• Forest provide employment large number of people and also help in generating revenue.

Question 7.
Suggest some approaches towards the conservation of forests.
Answer:
Basic steps to save forests :

• Trees: It’s a concept originally devised from elementary school audience but serves well as set of principles for saving rain forests and on a broader scale, ecosystems around the world.
• Teach, others about the importance of the environment and how they can help to save forests.
• Restore: Restore damaged ecosystems by planting trees, where forests have been cut down.
• Encourage: People to live in away that doesn’t hurt the environment.
• Establish parks : To protect forests and wild life parks should be established.
• Support : Companies that operate in ways that minimize damage to the environment.

Question 8.
Natural resources are decreased more rapidly. Guess what will be the consequences?
Answer:
The problem arising the exploitation of natural resources are the following.

• Natural resources like soil, water, air, forest, animals, minerals are declining at a rapid pace due to indiscriminate use.
• Deforestation leads to desertiflcation. downfall of rain, soil erosion, extinction of species.
• Air, water, soil pollutions leads ozone depletion Greenhouse effect.
• Soil also very precious natural resources if farmer want good yeild, they need healthy soil. If the activities of human continues with no time total soil become barren.
• Water is also very valuable resource only 3% water on earth available for our utility. If water pollution goes on like this. Availability of portable water very little for us.
• If human activities are not proper there lot scope for natural calamities like earthquakes, tsunami, floods will occurs. This lead perish of human race on the earth.

Question 9.
Prepare a questionnaire to conduct an interview at a petrol filling station personnel about consumption of fossil fuels?
Answer:
Questionnaire:

• What is the storage capacity of petrol filling station?
• How much petrol is consuming per day?
• From where the petrol is importing?
• Is the consumption of petrol increasing or decreasing?
• What are the chemicals present in it?
• How can a person save petrol?
• What is the alteriïate source for petrol if it is exhausted?
• What is the rate of importing petrol?

Question 10.
Prepare model for rain water harvesting/energy saving/soil management, reflecting your innovative thoughts.
Answer:

Procedure to prepare a model for rain water harvesting:

• Make a model of a house with roof little slanting towards one side.
• Connect a tube/pipe to the down end such that the rain water that falls on roof can be collected.
• Connect the other end of this tube to a barrel like structure which can be used as storage tank.
• From the tank arrange a tube towards the garden along with a valve that can be closed and opened.
• Arrange one more tube with valve into a recharge pit or percolation pit arranged at one corner.
• Arrange a tap to the tank that can be opened to collect the water for cleaning floor, vehicles, etc.
• During rain, water from roof can be collected into tank and we can utilize it later for gardening or cleaning purposes.
• When water is in excess it can be used to recharge underground water.

Question 11.
List out names of villages farmers and procedure followed for restoration of any natural resource in your area.
Answer:

 Village Name Farmer’s Name Procedure followed to restoration of natural resources Chilkoor Ch. Ramaiah Constructed recharge pits to restore underground water. Siddipet Seethaiah Constructed check dams to restore underground water. Mangollu T. Ranganadh Recharged the well by building dykes in thenalla. Miryalaguda R. Sundararn Motivated the villagers to construct percolation pits. Uppal D. Raja Reddy Removed silt from the tank.

Question 12.
You might have heard the Natural Gas drillings near Kakinada by ONGC(Oil and Natural Gas Corporation). Collect information and prepare a note on the status of Gas production at the basin.
Answer:

• Presently ONGC producing gas at the rate of 3.05 MMM3/day to 4.0 MMM3/day.
• ONGC, GSPC, Reliance industries are companies exploring oil and natural gas in this region.
• GAIL is marketing and distributing the natural gas through gas collection stations.
• ONGC has established mini oil refinery at Tatipaka.
• ONGC is associated with GAIL in planning the additional facilities and technical inputs needed for the future enhanced gas supplies.
• Total allocation of natural gas from KG. area is 8.5 MMM3/day.
• ONGC has already projected a production potential of 6.5 MMM3/day of gas availability of which entire quantity has been allocated to the industrial consumers of that area.
• 16 Industries are actively using Natural gas investing Rs. 5500 crores are working well for power generation, steel re-rolling, producing fertilizers etc., and some power projects are almost invested Rs. 4000 crores and waiting for supply of Natural gas.

Question 13.
Does your village or nearest city has a recycling unit of waste materials? Write in detail the steps involved in it.
Answer:
Near to our village there is a center that recycles the paper waste. Here the waste paper is recycled in the following way.

• Waste paper is collected from various sources.
• This paper is taken to the recycling plant where it is separated into types and grades.
• The separated paper is then washed with soapy water to remove inks, plastic film, staples and glue.
• The paper is put into a large holder where It is mixed with water to create slurry.
• By adding different materials to the slurry different paper products can be created, such as cardboard, newsprints or office paper.
• The slurry is spread using large rollers into large thin sheets.
• The paper is left to dry.
• Then it is rolled up, ready to be cut and sent back to the shops.

Plastic Recycling process:

Stage – 1: Plastic needs to collected by the recycling company. Once plastic arise, recycling plant he first stage is to sort the plastic into specific types because plastic recycling is more complex than of other metals like glass or paper. Due to many different types of plastic, more importantly mixed plastic cannot be used in manufacturing without delivering poor quality products. Heñce why plastic recycling companies need to be through when it comes to sorting the waste plastic into the definite forms.

Stage – 2: Once the waste plastic is identified and separated, the cleaning process will begin, this usually starts with washing to remove paper labels, adhesives and other impurities to be completely removed as this lowers the quality of the recyclic plastic.

Stage – 3: The shredding stage is when the plastic is taken and loaded on to conveyor belts or directly into huge hoppers that funnel the clean scrap towards rotating metal teeth that rip the plastic into small pellets which are bagged up and ready for testing.

Stage – 4 : Identify and classify the plastic: Once the shredded plastic has been hagged it is then chemically tested and labelled as to its exact specification, this grade plastic can be used as is by adding to a mix of vergin plastic in a manufacturing run, alternatively the grade plastic can be further recycled.

Stage – 5 : Exturding: This is the final stage in recycling plastic. This involves cleaning and melting, shredded plastic and extruding the form of pellets which then go on to manufacture the next lot of plastic products.

Reasons to recyclic plastic: Millions of tons of a waste plastic end up in land fill, when the vast majority of it can be recycled, it’s all too easy to throw away rubbish without a second thought, but we need to take care of our planet and not just reducing the amount of rubbish we bury but also given that plastic is derived from oil, a natural product with ever depleting resource it makes sense to recycling as much as possible.

Question 14.
Collect any graph that shows oil (petroleum) consumption in India.
i. Does the production meet consumption in India?
ii. During which period of time shows highest increase in consumption rate?
iii. What change have you observed in the production from past ten years, for example 2006-2016?
iv. Suggest some ways to bring down consumption of petroleum.
Answer:

i. No, the production does not meet consumption of India.
ii. During 2008 to 2016 the consumption rate is highest.
iii. Running rate of vehicles is increasing enormously due to increase in population but the production is not increasing as per the consumption.
iv. Everyone can help conserve fossil fuels by using them carefully.

• Turn off lights and other electronics, when we are not using them.
• Purchase energy-efficient appliances.
• Walk, ride a bicycle and use public transport whenever possible.
• It is better to prefer public transport system like bus or train instead of travelled in personal vehicles.
• Minimise fuel wasted in idling.
• Practice eco-friendly methods.
• Don’t use car when you are travelling alone.

Question 15.
Proper utilisation of natural resources is the way to show gratitude to our nation. Can you support this statement? Give your argument.

Question 16.
Crop selection and cultivation should be based on availability of water. Prepare a slogan to bring awareness among farmers about this?

### TS 10th Class Biology 10th Lesson Natural Resources Intext Questions

1 Mark Question and Answers :

Question 1.
If water resource becomes scarce, will it affect the nature of soil in an area?
Answer:
Yes, it will also affect the nature of the soil in an area.

Question 2.
As wells dry up, how are people In the area dependent on the well affected?
Answer:
Open wells have dried up, water tables have gone down.

Question 3.
Why do you think water became scarce mainly in Vaddicherla?
Answer:
Water is pumped out of wells and bore wells using electricity leads to water scarcity.

Question 4.
What could have saved water in Vaddicherla?
Answer:
Following the Micro – Irrigation and developing the ground water succees could have saved water in VaddicherlAnswer:

Question 5.
A well irrigates more area in Kharlf season as compared to Rabi, how Is it possible?
Answer:
A well irrigates more area in Kharif season as compared to Rabi because Kharif occurs in rainy season and Rabi in winter season. So well irrigation is more in Kharif season.

Question 6.
How should a farmer utilize such a condition?
Answer:
Farmer wants to irrigate more land in Kharif season to grow more crop to get more yield.

Question 7.
How can wells be recharged?
Answer:

• Wells can be recharged by constructing the soak pits.
• Soak pits trap rain water optimally and helps in recharging the dried up wells.

2 Mark Question and Answers :

Question 1.
How would recharging dried up wells help farmers of Vaddicherla?
Answer:

• Recharging dried up wells helps to increase the availability of water.
• Cost involved in irrigation will decrease.
• Production will increase.
• As a result, the farmers of Vaddicherla will get into net income.

Question 2.
What does the case tell us about a water resource and its effect on farmers?
Answer:

• This case tell us that the water resource is very crucial for farmers.
• If they don’t utilise these resources in a proper way. they may not get this in sucientquantit
• This condition leads to less productivity and more investment.
• So the farmer will gét the losses or less benefited.
• So this resource should be properly used and conserved.

Question 3.
Why were farmers at Wanaparthy at a better state than those at Vaddicherla?
Answer:
Farmers at Wanaparthy are at better state than those at Vaddicherla because

• They conserve the water by converting a existing tank into percolation tank. As a result, water situation is much better than Vaddicherla.
• Dug wells were converted into bore wells to reduce loss of water by surface evaporation.
• By selecting dry land crops using Jess water expenditure on irrigation was reduced.

Question 4.
How did farmers of Vaddicherla and Wanaparthy recharge their ground water resources?
Answer:

• The farmers of Vaddicherla and Wanaparthy recharged their ground water resources by constructing soak pits.
• Soak pits stores rain water optimally.
• It helps in recharging dried up bore wells.

Question 5.
What ways of restoration of a resource does the Kothapaily case tell us about?
Answer:
The Kothapally case tells us about the following ways of restoration of a resource:

• Construction of water storage structures.
• Percolation pits.
• Contour field bunding.
• Recharge of wells by building dykes or barriers in the nalla.
• Plantation in waste lands.
• Adapting micro-irrigation techniques.

Question 6.
What are some common means of restoration and conservation of water resource that we came across in the cases studied so far?
Answer:
The common means of restoration and conservation of water resource that we come across in the cases studied are:

• Percolation pits
• Micro-irrigation techniques
• Soak pits.

Question 7.
How do you think we will meet our requirements in future?
Answer:
We have to meet our requirements in future by

• Desalinating the sea water.
• Restoring of ground water by recharging with rain water.
• Getting co-operation from the neighbouring states.
• Conserving water now for future.

Question 8.
We would have to depend upon other states or perhaps other countries for water. Do you agree ? Why/Why not?
Answer:
Yes, I agree with this statement. Because.

• If water not observed today, a situation may arise where we have to depend upon other states or perhaps other countries as well.
• But mostly condition of all the states òr countries may be more or less similar at a point of time.
• So mutual co-operation regarding water may be needed.

Question 9.
Could the amount of water used for irrigation in our state be reduced ? How?
Answer:

• The amount of water used for irrigation in our state can be reduced.
• For this, micro-irrigation techniques such 35 drip irrigation, sprinkler irrigation should be adapted.
• Seed based irrigation should be done.
• Crops that require less water should be grown.

Question 10.
Does cropping pattern have any role to play in reduction of water utilisation?
Answer:

• Cropping pattern also had a key role to play in reduction of water utilisation.
• Using alternative crops. one using more water and second one using less water can conserve water some extent.
• Dry Land crops should be grown when there is no proper availability of water.
• Usage of less water harvesting system like drip irrigation and sprinklers.
• Cultivation of commercial crops.

Question 11.
Do you think one needs laws for distribution of water and its use ? Why/Why not?
Answer:

• Yes, laws are need for distribution of water and its use.
• Otherwise all the people may not have self discipline to conserve water.
• As water is a key resource for life, competition may arise between people or states or countries.
• Laws help to control this kind of dispute and use it judiciously.

Question 12.
How much percent of area do you think is irrigated by other sources of water?
Answer:

• Inspite of some major rivers like Godavari and Krishna, the major source of irrigation is ground water.
• In our state 43% of area under irrigation is through ground water.
• 37%, 15% and 5% of area under irrigation are getting water through canals, tanks and other sources respectively.

Question 13.
Why do the rivers fail to benefit the state to an extent they should have?
Answer:
Rivers fail to benefit the state to an extent they should have. Because

• There are no sufficient structures (dams) to store river water.
• Over usage of water by the other states.
• Geographically our rivers are flowing through the rocky and hill areas in most of the places in our state where it is difficult to make canals.
• Government should plan for proper utilization of river water after scientific study with the help of expert engineers.

Question 14.
Since ground water resources are getting depleted at a fast pace. What are the alternatives?
Answer:
Since ground water resources are getting depleted at a fast pace, the alternatives are:

• Tanks should be constructed to harvest rain water.
• Projects should be constructed across the rivers.
• Water stored in projects or dams should be channelised to the agricultural lands through canals.

Question 15.
How should states and countries work to provide enough for all?
Answer:
States and countries can work to provide enough water for all by,

• Making some strict laws for distribution of water and its use.
• Every state or country should obey and follow these laws very strictly.
• There should be some autonomous body to look after the agreements and disputes between the states or countries.
• There should be co-operation for water between the states or countries to provide enough water for all.

Question 16.
What would you do to motivate others to manage an important resource in your locality?
Answer:
To motivate others manage an important resource in my locality I will do the following activities:

• I will explain the importance of resource and need for its proper management.
• I will conduct the seminars on this issue.
• With the help of my friends and teachers i will conduct some competitions like debet, essay writing, etc., on this issue.
• I will plan some cultural activities such as songs, skits that explain the importance of managing the resource and exhibit them in the school and the village to motivate the village.

Question 17.
Observe a lawn in your area (if you have one) and see how It is maintained. Find out from the gardener the different types of plants that he removes from time to time. Do you think a farmer does the same thing on his farm?
Answer:
The gardener removes all the species of plants that grow in the lawn from time to time. Farmer does the same thing on his farm. Hut the variation is all the plants are removed from lawn just for pleasant look whereas farmer remove only weed plants that compete with the crop plants for space, nutrients, water and sunlight. This is to incase the productivity of crop plants.

Question 18.
What do fossil fuels provide us?
Answer:

• Fossil fuels provide us energy.
• This energy can be used for various purposes such as running vehicles, machinery in industries, etc.
• They are also useful in the production of electricity.

Question 16.
What would you do to motivate others to manage an important resource in your locality?
Answer:
To motivate others manage an important resource in my locality I will do the following activities:

• I will explain the importance of resource and need for its proper management.
• I will conduct the seminars on this issue.
• With the help of my friends and teachers i will conduct some competitions like debit, essay writing, etc., on this issue.
• I will plan some cultural activities such as songs, skits that explain the importance of managing the resource and exhibit them in the school and the village to motivate the village.

Question 17.
Observe a lawn in your area (if you have one) and see how it is maintained. Find out from the gardener the different types of plants that he removes from time to time. Do you think a farmer does the same thing on his farm?
Answer:
The gardener removes all the species of plants that grow in the lawn from time to time. Farmer does the same thing on his farm. Hut the variation is all the plants are removed from lawn just for pleasant look whereas farmer remove only weed plants that compete with the crop plants for space, nutrients, water and sunlight. This is to in case the productivity of crop plants.

Question 18.
What do fossil fuels provide us?
Answer:

• Fossil fuels provide us energy.
• This energy can be used for various purposes such as running vehicles, machinery in industries, etc.
• They are also useful in the production of electricity.

Question 19.
Why do we need to conserve the fossil fuels?
Answer:

• Fossil fuels are non-renewable resources.
• If once they are used up, they never replanish again or take several thousands of years to replanish.
• They become integral part of our life, that we cannot live without these.
• So, we need to conserve fossil fuels so that we don’t run out of them.

Question 20.
What other things could you reuse to save our resources?
Answer:
Things that can be reuse to save our resources are

• Water
• Paper
• Metals like iron, steel, etc.
• Plastic

Question 21.
Why should one sort wastes carefully before discarding them from home?
Answer:

• If the wastes are sorted carefully before discarding them from home, there are certain advantages.
• We can plan and recycle the waste.
• Biodegradable waste can be used to prepare manure.
• Paper, metals or any other materials that can be reuse or recycle can be utilised.
• Non-biodegradable materials such as plastic which cannot be recycled can be discarded.

Question 22.
Often we keep a plastic bagin our dust bins to discard waste, is Ita good practice?
Answer:

• Some people keep a plastic bag in dustbins to discard waste. This is for their convenience in discarding.
• But it is not at all a good practice.
• Plastic is nonbiodegradable, takes several years to mix with the soil.
• When plastic bags are discarded along with the waste. They never mix with soil, and causes soil pollution.
• When vegetable waste is discarded in plastic bag, if any animal feed on it, they enter into their stomach and cause problem.
• If they are discarded into drainages, they block the flow of sewage water, stagnation of drainage waste creates unhygenic conditions, helps mosquito growth and causes diseases.
• If this waste reaches soil, pollution of soil occurs which deplets soil health.

Question 23.
Discuss about various programmes to implement ‘recover’ to prevent environmental threat.
Answer:
To regrow the trees in other areas which are cut during construction. Recycling of waste materials decreases the scope of the land and air pollution. Treat the polluted water resources to decrease the water pollution.
Ex : Ganga water treatment policy. To decrease the particulate matter in air by using the air filters. To use public transports and reduce personal cars usage to recover the air pollution.

4 Mark Question and Answers :

Question 1.
Data at the beginning of the study
Answer:

 Village Total Area in acres (approximately) Area Under Irrigation Number of Wells Wanaparthy 4000 1000 155 Vaddicherla 3000 450 175

a. What is the total irrigated area (in acres), in Wanaparthy ?
Answer:
The total irrigated area in Wanaparthy is 4000 acres.

b. If one needs to irrigate all the land in Wanaparthy, how many wells would be required ?
Answer:
Number of wells required to irrigate all the land in Wanaparthy are 620.

c. Will the area under irrigation change due to increase in population Why / Why not ?
Answer:
No, the area under irrigation change due to increase in population.

Question 2.
Data after five years

 Village Area under irrigation (in acres) Number of wells Wanaparthy 860 95 Vaddicherla 315 56

a. If the number of wells were 95 how many have dried up?
Answer:
60 wells were dried up. (155 – 95 = 60°)

b. How does ‘decline in number of wells’ affect area under cultivation?
Answer:
Decline in number of wells represents fall of ground water levels due to less rainfall.

c. How would crops be affected due to decline in the number of wells ?
Answer:
The crops do not grow well and the yield is less due to decline in the number of wells.

d. Which village do you think is more affected ?
Answer:
Vaddicherla is more affected.

e. Should people in these villages continue to grow paddy ?
Answer:
No. the people in these villages should not continue to grow paddy.

Question 3.
Annual expenditure on well irrigation for small and large farmers
Answer:

 Village Land holding of Farmer Depth of bore well (In feet) Total cost of well irrigation per acre per year in rupees Wanaparthy Large 130 – 200 25000 – 70000 Small 110-180 25000 – 65000 Vaddicherla Large 90-300 22000 – 50000 Small 60 – 200 20000 – 45000

a. If a well can irrigate 2.5 percent of Irrigated land in rainy season, how many wells would irrIgate 860 acres of land?
Answer:
A well irrigation land 2.5 percent.
Land = 860 acres.
Required wells = $$\frac{860}{2.5}$$ x 100 = 34,400

b. Which factor has a greater effect on expenditure, number of wells or dep a well?
Answer:
Depth of a well has greater effect on expenditure.

c. What is the total expenditure on a small irrigated land owned by a farmer in Vaddicherla? How do you think a farmer meets this expenditure?
Answer:
The total expenditure on a whole cultivable land owned by a small farmer in Vaddicherla is a round 20,000 – 45,000 rupees per acre per year. The small farmer meets this expenditure through agricultural loans from banks.

d. What could help the farmer reduce expenditure? (Hint: think of crops that require less water)
Answer:
Cultivating the crops which require less amount of water.

e. Do you think increasing the depth of bore well is a good solution for Increasing total land area under irrigation? Why/Why not?
Answer:
Increasing the depth of bore well is not a good solution for increasing total land area under irrigation. This is because with increasing depth, expenditure also will increase so net profit will decrease. Moreover, ground water level decreases much more and has to dig more depth.

Question 4.
Income on crops

 Village Land holding of Farmer Net income per acre in Rupees Total income per acre year in rupees Paddy Kharif Paddy Rabi Cotton Gingelly Wanaparthy Large 8200 8700 4900 3300 25100 Small 7046 8490 10889 3110 29535 Vaddicherla Large 10698 5970 4000 3595 24263 Small 9128 7380 3031 2650 22189

a. Which crop is most profitable for a small farmer in Vaddicherla ?
Answer:
For a small farmer in Vaddicherla, Paddy in Kharif is more profitable.

b. What is the difference between a farmer in Wanaparthy and Vaddicherla with small land holdings ?
Answer:
A small farmer in Wanaparthy is getting more net income on Rabi paddy, Cotton and Gingelly whereas small farmer in Vaddicherla is getting more income on Kharif paddy. In total, small farmers in Wanaparthy are getting more income than farmers in Vaddicherla as they are using water resource properly.

c. Which crop could replace paddy and be profitable for a farmer in Wanaparthy ?
Answer:
If cotton replaces paddy, it will be profitable.

d. Though we know that paddy consumes maximum water, why do you think farmers still like to grow paddy ?
Answer:
Though paddy consumes maximum water, farmers believe that it is profitable and less risky. So they still like to grow paddy.

e. What is the impact of a depleting resource upon the farmers ?
Answer:
Depleting resource increases the cost of production. So the farmers are becoming poor and poor as cost increases and profit or income decreases.

f. Do you think the income of a farmer with small land holding in Vaddicherla is sufficient to meet his expenditure ?
Answer:
No, the income of a farmer with small hand holding in Vaddicherla is not sufficient enough to meet his expenditure.

g. Do you think farming as an occupation is profitable for farmers in Vaddicherla ?
Answer:
No. Farming as an occupation is not profitable for farmers in Vaddicherla.

h. Would the farmer have to look for other kind of occupations to meet his needs ?
Answer:
No need to look for other kind of occupations to meet their ends, but has to select proper crops that requires less water, proper methods that increase ground water, proper devices to use water discriminately.

Question 5.
How can we use water judiciously?
Answer:
We can use water judiciously by

• Using only required quantity of water.
• Minimising the waste.
• Developing methods to use less water and get more benefits out of it.
• Reusing once used water.
• Recycling of the water.
• Recharging the ground water.
• Adapting micro irrigation techniques in agriculture.
• Not polluting the water sources.

Question 6.
What do you think will happen If we do not take care of the sources of water?
Answer:
If we do not take care of the sources of water.

• The water becomes scarce.
• There will be no sufficient water for agriculture.
• Agricultural productivity will decrease.
• Food scarcity may arise.
• Demand will increase for Agribased products.
• Poor people may not get proper nutritious food as the cost is more.
• Proper drinking water may not available.
• Fluorine level in ground water will increase, who’s consumption may lead to fluorosis.
• Disputes may arise between different states and countries for water resources.
• Sea water introstion occurs and all the ground water will become salty in coastal regions.
• Fertile lands may become like deserts.

Question 7.
Why is it important to recharge the ground water sources?
Answer:

• Recharge of the ground water sources is very important.
• This is because nearly 43% of irrigating land is getting water from ground.
• Due to over drilling of bore wells and pulling out of water using electric motors, the ground water level is decreasing day by day.
• If it goes on without recharging, ground water becomes scarce.
• It shows impact on agriculture, the productivity wilt decrease.
• Fluorine level in ground water will increase.
• Saline water may intrude into the interior places of land and water becomes unfit for both drinking and agriculture.
• Farmers have to drill the bore wells to more depths which increase the losses for them.

Question 8.
How did the villagers in Kothapally resort to sustainable management?
Answer:

• The villagers in Kothapally resort to sustainable management with the help of ICRJSAT.
• ICRISAT educated villagers by large and provided technical support for cost efficient water storage and soil conservation structures.
• The measures were community as well as individual farmer-based.
• Fourteen water storage structures with the storage capacity of 300 to 2000 m3, 60 mini percolation pits, field bunding on 38 hectares were completed.
• Twenty-eight dry open wells, near Nalla were recharged by building dykes in the NaNa and retaining the run off rain water in it.
• A user group was formed for each water storage structure and the water collected was exclusively used for recharging the ground water to the dried well.
• Broad bed furrow land form and contour planting was implemented to conserve soil and water.
• Gliricidia plants are planted on the field bunds to strengthen the land, make the soil nitrogen rich.
• Farmers were encouraged to use water resources jointly and irrigate land using micro-irrigation techniques.
• Saplings of useful species were planted along the roads, field bunds and Nallas.

Question 9.
Why do you think forests are important?
Answer:
Forests are important because,

• They are rich habitat for plants and animals.
• They serve as a lung for the world.
• They purify air, decrease carbon dioxide, global warming and green house effect.
• Thus provide various valuable things such as wood, medicines, etc.
• They are providing raw materials for several industries.
• They maintain ecological balance in nature.
• They preserve the soil fertility.
• They cause rains.

Question 10.
Collect information about solar, wind, tidal and water power and prepare a scrap book Collect Information about conventional energy sources from internet and prepare a note on it.
Answer:
Solar energy: To use solar energy is to generate electricity from sunlight. For this purpose special chemical substances which are sensitive to light have been developed. When light falls on these substances, small chemical current is generated. This material is coated on a metal plate and this is used for producing large amounts of electricity. This current can be stored and used when needed. Watches, calculators, street lamps have been invented which use the current produced by light falling on light sensitive material.

Wind energy : Wind mills are in use for centuries especially for pumping water from wells. In wind mills, wind rotates the blades of wind will and is used to move the pistons and lift the water from the well. In earlier days, the fan blades of wind mill were made of wood or thin metal sheets which were heavy and inefficient. In recent years, wind mills are made of tough, strong, light weight plastic material and wind energy is being used to pump water and to run turbines for the production of electricity.

Tidal energy: Large amounts of energy (kinetic energy) is stored In the waves especilally in seas. Special devices have been made to rotate as the water passes through them by the wave action. This is used to run turbines or generate electricity.

Water power: Dams are constructed across the rivers. Water from the reservoir falls from a height on the turbines.This water falls is used to drive turbines to generate electricity. These are called hydro electric projects.

Question 10.
Collect information about solar, wind, tidal and water power and prepare a scrap book Collect Information about conventIonal energy sources from internet and prepare a note on it.
Answer:
Solar energy: To use solar energy is to generate electricity from sunlight. For this purpose special chemical substances which are sensitive to light have been developed. When light falls on these substances, small chemical current is generated. This material is coated on a metal plate and this is used for producing large amounts of electricity.

This current can be stored and used when needed. Watches, calculators, street lamps have been invented which use the current produced by light falling on light sensitive material.

Wind energy : Wind mills are in use for centuries especially for pumping water from wells. In wind mills, wind rotates the blades of wind will and is used to move the pistons and lift the water from the well. In earlier days, the fan blades of wind mill were made of wood or thin metal sheets which were heavy and inefficient. In recent years, wind mills are made of tough, strong, light weight plastic material and wind energy is being used to pump water and to run turbines for the production of electricity.

Tidal energy: Large amounts of energy (kinetic energy) Is stored In the waves especilally in seas. Special devices have been made to rotate as the water passes through them by the wave action. This is used to run turbines or generate electricity.

Water power: Dams are constructed across the rivers. Water from the reservoir falls from a height on the turbines.This water falls is used to drive turbines to generate electricity. These are called hydro electric projects.

Question 11.
Ask your teacher about nuclear energy and Its impacts on ecosystem.
Answer:
Nuclear energy is produced by splitting the nucleus of an atom of elements like uranium or plutonium. Another process for the production of nuclear energy is called fusion. In this process two nuclei of the same elements are fused with one another. In this process much more energy is produced than by fission reaction. This energy is produced as heat.

This is used to produce steam which runs generators to produce electricity. There are some problems associated with genergation of nuclear energy. Several precautions have to be taken to prevent leakage of radioactive toxic materials from nuclear reactors. The uranium required for nuclear reactor is processed at nuclear fuel complex in Hyderabad.

Question 12.
Do you think it is necessary to have a lot of lighting for decoration during celebrations?
Answer:

• No, it is not necessary to have a lot of lighting to decorate an occasion of celebration.
• Decorating with more lights consumes more electricity.
• Excess use of electricity leads to energy crisis.
• Most of the electricity is produced from fossil fuels like coal or diesel (generator).
• So it leads to depletion of our natural resources.
• Excess production of electricity from coal increases global warming.
• Thus it leads to changes in the environment and pollution also.
• So electricity should be used discriminately.

Question 13.
Collect information about technology used for transplantation of trees and discuss in your classroom.
Answer:
The tree transplantation technology involves the following procedures.

• Initial preparation by examining roots and tree health.
• Soil sampling and site selection.
• Root purning and initiating fresh root growth.
• Tree packing, feeding and monitoring for adaptation.
• Tree transplantation by lifting with crane.
• Mechanical support and purning.
• Post translational treatment.

Question 14.
Suggest some ways in which you and your friends would like to manage a resource.
Answer:

• Me and my friends can manage the biodiversity in our school.
• First we will make a map of our school.
• By studying we can identify various plants, insects and small animals like squirrels, etc. growing in our school.
• We will mark the details in the map and note down the details in a notebook.
• By dividing ourselves into various groups we will take care of flora and fauna.
• We will water the plants regularly.
• We will provide proper protection to both flora and fauna.
• Thus we can manage a resource.

Question 15.
Are we also an important resources of nature? How?
Answer:

• Natural resource are resources that we get from nature.
• We are also a part of this nature.
• Fauna is also a natural resource, actually we come under this category.
• The human beings are the most intelligent animals on the earth.
• We are capable of bringing changes in nature and utilize the other resources of nature effectively using our intelligence.
• Like the other resources, we are also useful to the nature in one or other way.
• Knowledge and intelligence are the key factors for the resourcefulness of a person.
• Thus we are also an important resource of nature called human resources.

Question 16.
Find out the usage of water in litres per day in your home ? Do you actually require that much water and how much water is enough in accordance with National standards?
Answer:

• In my house 900 litres of water is being used per day at the average of 225 litres for a person per day (4 members family).
• Actually this much water is not required.
• We can conserve atleast 400-500 litres of water at the average of 100 to 125 litres per head.
• In India, the design of water supply system has been done using certain standards.
• Currently the standard being used is BIS 1179: 1993, reaffirmed in 1998.
• According to this, for communities with a population between 20,000 to 1,00,000 – 100 to 150 litres per head per day can be considered.
• For communities with population over 1,00,000 – 150 to 200 litres per head per day can be considered.
• On the whole, at an average of 150 litres per head per day is enough in accordance with National standards.

### TS 10th Class Biology 10th Lesson Natural Resources Activities

Activity – 1.

Study the different ways in which water Is used, misused and recycled in the area where you stay. Prepare a questionnaire with the help of your friends and teacher and study at least five households in your locality for the same. Also explore and discuss ways to provide water for all. Ways in which water is used:
Answer:

• Drinking
• Bathing
• Washing clothes
• Cleaning utensils
• For plants in garden and agriculture, etc.

Ways in which water is misused:

• Not closing the taps after using.
• Contaminating the water.
• Brushing near open taps.
• Getting bath under shower
• Playing with water.
• Washing vehicles with water pipe.

Ways in which water is recycled:

1. Allowing the water used in kitchen for garden.
2. Using the once-used water to wash vehicles.
3. Using the water from bathing for toilet flush.
4. Washing hands in plant pots.

Questionnaire:

1. For what purposes water is being used in your home?
2. From where this water is being collected?
3. Are you using water only for the needed things?
4. Are you closing taps properly after using?
5. Are you getting shower bath?
6. Are you using more water than required for cleaning, bathing, etc.?
7. Are there any leaks in your water pipelines?
8. Are you recycling the once used water?
9. In what way are you recycling the water?
10. What measures do you suggest to conserve water and make it available for all?

Ways to provide water for all:

1. Wastage of water should be strictly minimised.
2. Washing hands in the plant pots.
3. Rain water should be directed into recharge pits.
4. Care should be taken to prevent leakage of water from pipes and taps.
5. Wash clothes in running water canals if possible.
6. Direct the kitchen water free from soap and detergents to the garden.
7. Use the soap and detergent water for toilet flush or cleaning vehicles.
8. Recycling of water can be done on large scale towns and cities and can be utilised again.
9. Cooperation between the states through which a river passing is very essential for providing water for all.
10. People should be motivated in such a way that each drop of water is life and should conserve it.

Activity – 2.

Find out how many different types of insects are present In and around your house. Do you find the same type of insects in all seasons ? Make a chart of Insect types and not their occurrence for at least a week in each season. Repeat for other seasons. Study for a year and find out when you have highest varieties of them. Study them for subsequent years to see if they have disappeared.
Answer:
Different types of insects present in arid around our houses:

• Cockroach
• Housefly
• Grasshoppers
• Mosquitos
• Mites
• Beetles etc.

Different insects are found in different seasons.

In summer and rainy seasons we can find highest varieties of these. Their population is maintaining almost standardly.

Activity – 3.

Nowadays people are revolting against mining. Collect any such incident of our state or neighbouring states from school library or newspapers and conduct a seminar on its impact.
Answer:

• People living in hill top hamlets in seven mandais of Visakhapatnam and East Godavari districts are up in arms against latente mining in Nagulakonda hill range.
• Latente is a raw material used by cement factories.
• Huge deposits of latente worth hundreds of crore rupees are found in Nathavaram and Koyyuru mandates in Visakhapatnam and Pratthipadu, Yeleswaram, Sankhavaram, Routulapudi and Kotananduru in East Godavari.
• AH these mandais are technically corning under scheduled areas.
• if the mining continues here, it will badly threaten the ecology of that area.
• The tribal people in that area will lose their livelihood.
• To reach the mining area road should be laid in the reserve forest area.
• This leads to depletion of forest resources also.
• Health of the local people will be badly affected due to the dust spread during mining.
• Keeping all these in mind the tribal people are opposing the mining in that area.

## TS 10th Class Biology Study Material 9th Lesson Our Environment

Telangana SCERT 10th Class Biology Study Material Telangana 9th Lesson Our Environment Textbook Questions and Answers.

## TS 10th Class Biology 9th Lesson Questions and Answers Telangana – Our Environment

Question 1.
What happens to the amount of energy transferred from one trophic level to the next in a food chain?
Answer:

• Energy is transferred along food chains from one trophic level to the next.
• But not all of the energy available to organisms at one step can be absorbed by organisms at the next one.
• The amount of available energy decreases from one stage to the next.
• This is because, not all the food can be fully digested and assimilate.
• Hair, feathers, insect exoskeletons, cartilage and bone in animal foods, cellulose and lignin in plant foods cannot be digested by most animals.
• These materials are either ejected by defecation or regurgitated in pellets of indigested remains.
• Assimilated energy is available for the synthesis of new blomass (which is food for the next tropic level) through growth and reproduction.
• But organisms lose some biomass by death, disease or annual leaf-drop.
• Moreover, at each tropic level, organisms use the most of the assimilated energy to fulfill their metaboLic requirements – performance of work, growth and reproduction.
• As biological energy transformations are Inefficient, a substantial proportion of metabolized food energy is lost unused as heat.
• Only a small fraction goes to the eater at next tropic level.
• SLobodkin (1959) suggested that the transfer of energy from one tropic level to the next is of the order of 10%. But in 1974, Steele proved it to be 20 to 30%.

Question 2.
What do pyramids and food chain indicate in an ecosystem?
Answer:

• The pathway along which food is translerred from one organism to another in an ecosystem is called a food chain.
• Food chain shows that how energy passed from one organism to another.
• Apart from the food chain, pyramids are another type of representations which show flow of energy from one organism to another.
• Ecological pyramids are the graphical representation of the feeding level structure of an ecosystem by taking the shape of a pyramid.
• Pyramid of number indicates the population of organisms at each tropic level of a food chain in an ecosystem.
• Pyramid of biomass indicates the available food (biomass) as a source of energy at each tropic level of a food chain in an ecosystem.
• Pyramid of energy indicates the available energy at each tropic level of a food chain in an ecosystem.

Question 3.
Write a short note on pyramid of numbers for any food chain. What did you conclude from the pyramid of numbers drawn using:
(i) tree
(ii) insects
(iii) woodpecker
Answer:
a.

• The number of organisms in a food chain can be represented graphically in a pyramid of number.
• Each bar represents the number of individuals at each tropic level in a food chain.
• At each link in a food chain, from the first-order consumers to the large carnivores, there is normally an increase in size, but decrease in number.
• For example in a wood, the aphids are very small and occur in astronomical numbers.
• The ladybirds which feed on them are distinctly larger and not so numerous.
• The insectivorous birds which feed on the ladybirds are larger still and are only present in a small numbers, and there may only be a single pair of hawks of much larger size than the insectivorous birds on which they prey.

b.

• In the given pyramid, the producer is a large tree, primary consumers are small insects which are numerous in number and secondary consumers are woodpeckers which are comparatively less in number than insects.
• From this pyramid of number, we can conclude that sometimes the pyramid of numbers does not look like a pyramid at all.
• This could happen If the producer is a large plant or if one of the organisms at any tropic level is very small.
• Whatever the situation, the producer still goes at the bottom of the pyramid.

Question 4.
Draw the pyramid of biomass using the terms given below:
(i) grass
(ii) herbivores
(iii) predators
(iv) hawk
Answer:

• Biomass is organic material of biological origin that has ultimately derived from the fixation of carbon dioxide and the trapping of solar energy.
• This includes trees, shrubs, crops, grasses, algae, aquatic plants, agricultural and forest residues and all forms of human, animal and plant waste.
• Any type of plant or animal material that can be converted into energy is called “Biomass”.

Question 5.
How does the usage of toxics substances affect an ecosystem’? Write a short note on bioaccumulation and biomagnification.
Answer:

• Use of toxic materials such as pesticides, herbicides and fungicides creates new problems in the ecosystem.
• As these toxic materials are often indiscriminate in their action and vast numbers of other animals may be destroyed.
• Some of them may be predators which naturally feed on these pests, other may be the food for other animals.
• Thus causing unpredictable changes in food chains and upsetting the balance within the ecosystem.
• Some toxic substances have a cumulative effect.
• These toxins vary in their length of life as toxic substances.
• Some of them are degradable, can be broken down into harmless substances in a comparatively short time usually a year.
• Others are non – degradable which are potentially dangerous as they accumulate in the bodies of animals and pass right through food web.
• Being further concentrated at each step until animals at the top of pyramid may receive enough to do considerable harm.
• This process of entering of pollutants in a food chain is known as “Bioaccumulation”.
• The tendency of pollutants to concentrate as they move from one tropic level to the next is known as “Biomagnifications”.

Question 6.
Should we use pesticides to protect the crops and foods from pests? Or should we think of alternatives’? Write your opinion and the reasons for it.
Answer:

• We should think of alternatives. This is because, these pesticides are toxic chemical whose usage leads to Bioaccumulation and ßiomagnificatiofls.
• When we use pesticides they prevent our crop and food from pests effectively but indiscriminately destroys a vast number of other animals.
• This is causing unpredictable changes in food chains and upsetting the balance within the ecosystem
• Most of the chemical pesticides that contain mercury, arsenic or lead are non – degradable.
• They enter into food chain, accumulate in the bodies of animals and pass right through food web.
• Being further concentrated at each step until animals at the top of pyrâmtd may receive enough to do considerable harm.
• This may lead to the danger of extermination of some of our larger and more attractive species.
• This is one of the reasons for ever decreasing number of butterflies, bees, small and large birds.
• The adverse effect of pesticides on birds was proved by the studies of Royal Society for the protection of birds.
• Some of the pesticides are nerve poisons and might bring about changes in behaviour.
• As the human beings are at the end of the food chain, these pesticides may get accumulated in our bodies also. This shows some adverse effects on us, when their concentration becomes sufficiently high.

Question 7.
What is a trophic level? What does it represent in an ecological pyramid
Answer:

• Trophic level is the feeding position in a food chain.
• In an ecological pyramid, the first trophic level represents the primary producers, and their number, biomass or energy.
• Second trophic level represents the herbivores or primary consumers and their number, biomass or energy.
• Third trophic level represents the lower carnivores or secondary consumers and their number, biomass or energy.
• Fourth trophic level represents the higher carnivores or tertiary consumers, and their number, biomass or energy.

Trophic Levels:

II level carnivores — IV level

I level carnivores — III level

Herbivores — II  level

Producers — I level

Question 8.
If you want to know more about flow of energy in an ecosystem, what questions do you ask?
Answer:
I will ask the following questions to know more about flow of energy in an ecosystem.

• How does the energy flow in an ecosystem from one organism to other?
• Is the energy transformation from one level to other 100% efficient?
• What percent of energy transfers from one level to other?
• What happens to the remaining energy?
• How does the ecosystem lose its energy during energy transformation?
• Which tropic level in an ecosystem has more energy and which has less?
• What is the ultimate source of energy in an ecosystem?

Question 9.
What will happen if we remove predators from food web?
Answer:

• Removal of organisms from any tropic level of a food chain or food web disturbs the ecosystem and leads to ecological imbalance.
• If we remove predators from food web, the prey population will increase enormously as there is no natural control over them.
• The producers population will decrease rapidly as the organisms feeding on them increase.
• After few generations the prey population also begins to decrease as some of the preys begin to die due to starvation.
• Some adaptations may also be developed by the organisms to bring the ecological balance.
• But it may take some generations, till that the ecosystem will be disturbed and imbalanced.
• For example if we remove all the predators (carnivorous) from a forest ecosystem, the h herbivorous animal population will increase as there are no carnivores to hunt them.
• As a result plant population will decrease as the ever-increasing herbivores feed more and more on plants.
• After some generations the herbivore population begins to decrease as the decreasing number of plants are not sufficient to feed.
• Then some herbivorous animals may adapt to feed on other herbivores to increase their survival.
• Then scope for survival will increase for plants again which leads to ecological balance.
But this may take lot of time to evolve new predators and to form ecological balance.

Question 10.
Observe a plant in your kitchen garden, and write a note on producer-consumer relationship.
Answer:
When I observe a plant in kitchen garden, I came to know the following things.

• Though it may be relatively small, a garden is a complete ecosystem.
• It has the same components as any other large and elaborate ecosystems had.
• The plant in a kitchen garden is a producer as it produces their own food from sunlight.
• There are two types of consumers in this ecosystem.
a. Primary consumers and
b. Secondary consumers.
• Primary consumers feed on plants. This tropic level consists of caterpillars, bees and butterflies.
• Secondary consumers feed on primary consumers. This tropic level consists of birds, garden lizards and spiders.
• Fungi, bacteria, insects and worms make up decomposers.
• The producer and consumer relationship can be shown in the following food chain.
• Producers → Primary consumers → Secondary consumers
• The pyramid of number appears like this.
• The pyramid of Biomass appears like this
• The pyramid of energy appears like this

Question 11.
Collect information on laws and ethics concerned to the environment and display it on bulletin board.
Answer:

• We should have profound respect for Nature.
• We must maintain a hormonious relationship with other species.
• Everyone should take responsibility for his impact on nature.
• Local and indigenous environmental knowledge should be respected.
• We must plan long term.
• The Environment Protection Act (1986) enacts to protect and improve environmental quality, control and reduce pollution from all sources. The Hazardous waste rules (1989) controls the generation, collection, treatment, import, storage and handling of hazardous wastes. The Biological Diversity Act (2007) enacts to provide sustainable use of conservation of biological chemistry.

Question 12.
Draw a pyramid of numbers considering yourself as a top level consumer. Write about the lower trophic levels.
Answer:
The pyramid of numbers considering humans as top level consumer looks like a upright pyramid. There will be increase in the numbers from top to bottom. Man feeds on various animals like goat and birds like chicken, etc. These animals inturn feed on large number of insects and worms, or some herbivores can directly feed on plants. The lower tropic can directly feed on plants. The lower trophic layer consists of plants in larger numbers which produce energy. People who feed on the plants are called vegetarians and just lay above the first trophic level.

Question 13.
Prepare slogans to promote awareness in your classmates about ecofriendly activities.
Answer:

• Live and let live.
• If we protect environment, it protects us.
• Conserve nature – Conserve life.
• Save mother earth.
• Earth needs you.
• Go ecofriendly.
• Clean the environment, live happily.
• Heal our planet ! Turn into a better planet.
• Plant a tree for your environment.
• Think ecofriendly and live ecofriendly.
• Earth enables you to definitely stand. Allow it to stand the actual way it is.
• You’ve only got one planet. Don’t trash it.
• Say no to plastic.
• Encourage Bio-fertilizers,

Question 14.
Suggest any three programmes on avoiding pesticides and preventing soil pollution.
Answer:
Pesticides are the toxic chemicals which are used to destroy pests. They not only disturb the ecosystem but also pollute the soil. To prevent soil pollution caused by pesticides following programmes should be implemented.
i. Rotation of crops
ii. Biological pest control
iii. Development of genetic resistant strains.

i. Rotation of crops:

• Same crop should not be grown in the same field in successive seasons.
• As the pest which grows on one crop never grows on the other, they can be kept under control naturally.

ii. Biological pest control:

• In this method pests are controlled by some biological processes, instead of using chemical pesticides.
• Using predators, using hormones like pheramones, sterilization of the insect pests and utilisation of biological pest repellents such as neem oil etc., are some of the biological pest control methods.

iii.  Development of genetic resistant strains:

• Nowadays using genetic engineering pest resistant strains are being produced.
• If we use these, crops never get effected by the pest, so no need to use pesticides.

Choose the correct answer:

Question 1.
What does a food chain always start with?
A. The herbivore
B. The carnivore
C. The producer
D. None of these
Answer:
C. The producer

Question 2.
Which of the following do plants not compete for?
A. Water
B. Food
C. Space
D. All above
Answer:
B. Food

Question 3.
Ban all pesticides, this means that ……………
A. Control on usage of pesticides
B. Prevention of pesticides
C. Promote ecofriendly agricultural practices
D. Stop biochemical factories
Answer:
C. Promote ecofriendly agricultural practices

Question 4.
According to Charles Elton
A. Carnivores at the top of the pyramid
B. Energy trapping is high at the top of the pyramid
C. No producers at the top of the pyramid
D. A and C
Answer:
D. A and C

### TS 10th Class Biology 9th Lesson Our Environment Intext Questions

1 Mark Question and Answers :

Question 1.
Name any two pesticides / insecticides you have heard about.
Answer:
DDT, Aidrin, Malathian, Altrazine, Monocrotophos, Endosuiphan, etc.

Question 2.
Where do the pollutants enter the water sources from?
Answer:
The used water from industries and run off water containing agricultural effluents bring pollutants into water sources. Municipal and domestic sewage also pollute water sources.

Question 3.
How do heavy metals enter the fishes living in this water?
Answer:
The bioaccumulation of heavy metals in tissues of fish particularly in liver, kidney and gills were analysed and found their presence.

Question 4.
What is the food chain that has been discussed in the above case?
Answer:
The food chain discussed in the above occurrence is
Crops → Locust → Sparrow Hawk.

Question 5.
How did these disturbances affect the environment?
Answer:

• The number of locust increased.
• Use of pesticides against locust population further degraded the land.

Question 6.
Is it right fo eradicate a living organism in an ecosystem ? How is it harmful?
Answer:

• No, it is not right to eradicate a living organism in an ecosystem.
• It disturbs the existing food chain.

Question 7.
Were the sparrows really responsible ? What has the reason for the fall in crop production?
Answer:

• No, the sparrows were not really responsible for the loss of food grain.
• With no sparrows to eat the locust population crops were damaged and this led to fall in crop production.

Question 8.
What was the impact of human activities on the environment?
Answer:

• The human activities badly affected the environment.
• Use of pesticides against the pest degraded the landutions

2 Mark Question and Answers :

Question 1.
Are all terrestrial ecosystems similar?
Answer:
1) No. Ail the terrestrial ecosystems are not similar.
2) Based on variations in climatic conditions such as rainfall, temperature and the availability of light, there are various kinds of ecosystems.
3) The major types of terrestrial ecosystem are :

• Tundra
• Coniferous forest
• Deciduous forest
• Savannah
• Tropical forest and
• Deserts.

Question 2.
Why do most of the food chains consist of four steps?
Answer:

• Most of the food chains are quite short and mostly consistS of four steps.
• This is because only 10% of the energy present in a level transfers to the other level.
• Remaining energy is dissipated as heat produced during the process of respiration and other ways.
• Thus about three steps in a food chain very little energy is still available for use by living organisms.

Question 3.
Why do the number of organisms get decreased as we move from producer to different level of consume’s
Answer:

• As we move from producers to different levels of consumers the energy available will decrease gradually.
• Only ten percent of the energy present in one tropic level transfer to another tropic level.
• Biomass also decreases gradually as only 10 – 20% of the biomass is transferred from one tropic level to the next in a food chain.
• As there is less energy & less biomass available at top levels number of organisms also less, generally.
• So, the number of organisms get decreased as we move from producer to different level of consumers.

Question 4.
How are the food grains and cereals being stored in your house and how do you protect them from pests and fungus?
Answer:
To protect food grains and cereals from pests and fungus, we will follow the following rules in our house.

• First of all we will dry and clean our grain before storing.
• We will avoid moisture in bagged grains by storing them on wooden structures, bamboo mats or polythene covers.
• We use domestic bins or improvised storage structures such as Gaade, Kotlu, Paatara, RCC bins and flat bottom metal bins etc.
• We fumigate the storage room with Ethylene Di-bromide (EDB) ampoules to avoid insect damage.
• We use anticoagulants for rat control in houses.

Question 5.
Researchers found that pollution levels increase during monsoon season. Why they found so?
Answer:

• Pollution levels increase during monsoon season in water bodies.
• During monsoon season heavy rainfall occurs.
• The rain water brings residues of agrochemicals fertilizers and different types of organic substances, municipal and domestic sewage.
• Hence pollution levels increase in monsoon season.

Question 6.
Why did people living in the areas nearby the water reservoir, suffer from various diseases?
Answer:

• The heavy metals could find their way into human beings through food chain.
• This bioaccumumation cause various physiological disorders such as hypertension 1 sporadic fever, renal damage, nausea, etc.

Question 7.
How did the campaign disturb the food chain in the fields?
Answer:

• Crop yields after the campaign were substantially decreased.
• Though the campaign against sparrows ended it was too late.
• With no sparrows to eat the locust populations, the country was soon swarmed.
• Locust coupled with bad weather led to the great Chinese famine.

Question 8.
What do you suggest to stop/avoid such incidents?
Answer:

• I suggest to use organic manures and organic insecticides to kill the Insects.
• Rotation of crops is the best method to protect the crops from pests.
• We should not kill any organism on this earth because every organism has a role to play.
• Think before you start action.

Question 9.
What did scientists find in the sparrow campaign? Did they help in rectifying / correcting the mistake ? Why didn’t they do it so?
Answer:
During the sparrow campaign some scientists cut open the digestive systems of dead sparrows and found only one-fourth contained grains. This finding showed that sparrows are benificial birds for humans. This ended the campaign against sparrows but it was too late. There were no sparrows to eat the locust populations which led to the great Chinese Famine.

4 Mark Question and Answers :

Question 1.
If we want to show a food chain consisting of grass, rabbit, snake and hawk then connect the given picture of organisms by putting arrows and make a food chain.
A. Name the producers and consumers in the above food chain.
B. Try to guess what the arrows marked by you indicate.
C. Identify at least four other food chains from your surroundings. Name the producers and different levels of consumers in those food chains.
Answer:
Grass → Rabbit → Snake → Hawk
A. In the above food chain grass is the primary producer. Rabbit is the primary consumer, snake is the secondary consumer and hawk is the tertiary consumer.

B. The arrows indicate the flow of energy from one organism to another. So these are always pointed from the food to the feeder.

C.

• Plant → insect → frog → snake
• Aquatic plants → insects → fish → crane
• Plant → mice → snake → vulture
• Plant → aphids → spiders → birds

Question 2.
Draw the pyramid of number for the following food chains.
i. Banyan tree insects woodpecker
ii. Grass → rabbit → wolf
A. Does the pyramid of number have the same structure in both the cases as compare to the example given in the textbook?
B. If there is a difference, then what is it?
Answer:

A. No. The pyramid of number in the above two cases doesn’t have the same structure as compared to the example given in the textbook.

B.
1. In the example (given in the textbook), number of organisms at producers level is more. This number gradually decreased in consumers level step by step. So the pyramid of number formed has typical pyramid shape with broad base and the narrow apex.

2. But in the first case given here, on a single Banyan tree, a large number of insects live and feed. These insects become food for few Woodpeckers. So producers number is less than primary and secondary consumers, and secondary consumers are less than primary consumers. So the pyramid of number does not look like a pyramid. It consists of narrow base, broad middle part and medium apex.

3. In the second case, Grass which are large in number become food for few rabbits. Rabbit provides food for several wolf which are comparatively less in number than grass. So primary consumers are less in number than secondary consumers and producers. So the pyramid of number for this food chain also does not look like a pyramid. It consists of broad base, narrow middle part and medium apex. Thus it differs from case (1) also.

Question 3.
Think why the pyramids are always upright?
OR
Why are the pyramids always upright?
Answer:

• In ecology not all the pyramids are always upright.
• Pyramid of number may be upright, inverted or partly upright.
• Pyramid of biomass may be upright or inverted.
• But the pyramid of energy is always upright.
• This is because energy will decrease when we move from producers to the high level consumers.
• Only 10% of the energy from one tropic level transfers to the other through food chain.
• So the energy at base is more, gradually decreases, and very less at the top.
• As a result the energy pyramid is always upright.

Question 4.
Observe the data given in the following table.
Answer:

i. In which year lake-water spread area is more? Why?
Answer:
In the year 1967. Because lake was brought under cultivation.

ii. Why do you think weeds are more dense in the lake?
Answer:
Excessive nutrient addition, especially from anthropogenic sources, led to explosive weed growth. Ex: Eichornia, Pistia.

iii. What are the reasons for decrease in lake area?
Answer:

• ln 1996, almost entire lake was brought under cultivation.
• Industries came along in ever growing intensity in the catchment area of the lake.

iv. How do the above said reasons lead to pollution?
Answer:

• Consequently, the drains and rivulets carry substantial quantity of various types of pollutants into the lake.
• The major sources of pollution are agricultural runoff containing residues of several agrochemicals, fertilizers, fish tank discharges, industrial effluents containing chemical residues.

v. What could be the reasons for the migration of birds to this lake?
Answer:
To avoid extreme cold weather conditions in Northern Asia and Eastern Europe birds migrate to Kolleru lake.

vi. How was the threat to the lake due to pollution discovered?
Answer:

• The water of the lake turned alkaline in nature, turned, nutrient rich, low in dissolved oxygen and high in biochemical oxygen demand.
• Water borne diseases like diarrhoea, typhoid, amoebiasis and others are said to be common among the local inhabitants who are unaware of the state of pollution in the lake water.
• Vector-borne diseases also increase.

Question 5.
Observe the following table showing different activities in the lake and their influence.
Answer:

Legend: (+) means has influence on the mentioned problem
(-) means has no influence on the mentioned problem

i. What are the factors that affected the number of migratory birds to decrease?
Answer:
Aquaculture practices.

ii. Do you find any relationship between biological and physical problems ? What are they?
Answer:
Yes. Aquaculture practices have influence on these problems.

iii. What are the reasons for chemical problems?
Answer:
Agricultural practices, aquaculture practices, industrial activities and human activities are the reasons for chemical problems.

iv. What happens if the dissolved oxygen reduces in lake water?
Answer:
If the dissolved oxygen reduces in lake, water, then the water turned more alkaline in nature. Organisms die due to lack of sufficient amounts of oxygen.

v. Is BOD of turbid and nutrient rich water high or low? What are its consequences?
Answer:
High organisms in water die its consequences are water borne diseases.

vi. People living encatchment area of Kolleru faced so many problems. Why?
Answer:
Vector borne disease increased. The lands abandoned are useless for agriculture.

vii. How does pollution influence the migration of birds?
Answer:
Due to pollution the water of the lake turned more alkaline in nature, turbid, nutrient rich, low in Dissolved Oxygen (DO) and high in Biological Oxygen Demand (BOD).
This increased, a number of vector borne diseases. A large number of fishes are endangered. This decreases the migration number of birds.

### TS 10th Class Biology 9th Lesson Our Environment Activities

Observe any (water) ecosystem In your surroundings and identify the different food chains and food web operating in this ecosystem. Write the following details in your notebook.

1. Names of the students in a group : ………………….. Date : …………………..
2. Name of the ecosystem : …………………..
3. Topography : …………………..
4. Names / Number of plants (producers) identified : …………………..
5. Names / Number of animals identified : …………………..
6. Identify the different types consumers and name them & mention their number below:
Herbivores (Primary consumers) : …………………..
Carnivores (Secondary consumers) : …………………..
Top carnivores (Tertiary) : …………………..
7. Food relationships among them: food habits / preferences : …………………..
8. Show / draw the different food chains : …………………..
9. Showcase the food web I : …………………..
10. List out all abiotic factors existing in the ecosystem : …………………..
(A check list can be given, and asked to tick)
11 . Is there any threat to the ecosystem ? Yes / No : …………………..
If yes, what ? and how ? : …………………..
Suggest few remedial measures : …………………..

A. Student’s Activity.

## TS 10th Class Biology Study Material 8th Lesson Heredity and Evolution

Telangana SCERT 10th Class Biology Study Material Telangana 8th Lesson Heredity and Evolution Textbook Questions and Answers.

## TS 10th Class Biology 8th Lesson Questions and Answers Telangana – Heredity and Evolution

Question 1.
What are variations? How do they help organisms?
Answer:

• Differences in characters within very closely related groups of organisms are referred to as variations.
• Variations develop during reproduction in organisms.
• Sexual reproduction and errors in DNA copying leads to variations in offsprings in a population.
• Variations are passed from parent to offspring through heredity.
• Thus the variations accumulate over the generations.
• Beneficial variations are selected by the nature in evolution.
• These variations increase the survival chance of the organisms.
• These variations help the organisms to adopt to their environments.
• For example, green colour in the beetles is a variation that gave a survival advantage to the beetles as they cannot be seen by the crows.
• Accumulated variations gradually lead to evolution.

Question 2.
One student (researcher) wants to cross pure tall plant(TT) with pure dwarf(tt) plant, what would be the F1 and F2 generations? Explain.
Answer:

• When a pure tall plant (TT) is crossed with pure dwarf plant (tt), all the offsprings in F1 generation are tall.
• Pure tall plant has both the factors of the same type ‘TT’.
• Pure dwarf plant has both the factors of the same type ‘tt’.
• The breed after cross pollination will have one of the factors from pure breed tall (TT) and one from pure breed dwarf (tt).
• Thus all the plants will have the factor pair “Tt”.
• So all the plants are heterozygous tall, as ‘T’ is the dominating factor.

• On self-pollination of these, the new breed can have any combination of T and t.
• It can be TT, Tt, tT or tt. All of them are equal.

• But any plant that has a T factor will be tail.
• So in F2 generation 75% of plants are tall and 25% of plants are dwarf. Thus the phenotype ratio is 3: 1.
• Among 75% of tall plants, only 25% plants are pure tall (TT) or homozygous tall, remaining 50% plants are heterozygous tall (Tt, tT).
• The remaining 25% dwarf plants are pure or homozygous dwarf (tt).
• So the genotype ratio is 1: 2: 1.

Question 3.
One experimenter cut the tails of parent rats ,what could be the traits in offsprings? Do the daughter rats contain tails or not? Explain your argument.
Answer:

• If the tails of parent rats were cut, their offsprings will have normal tails.
• This is because the bodily changes which may occur due to environment won’t be passed to its offspring.
• Cutting of tail will not change the DNA of the germ cells, it is a bodily change. Therefore loss of tail is not a trait that can be inherited by progeny of tailless rats.
• Augustus Weisemann did this experiment on rats to test the theory of “Inheritance of acquired characters” proposed by Lamarck.
• He removed tails of parental rats.
• He observed its offsprings which have normal tails.
• He has done it again for twenty two generations but offsprings are with normal tails.
• Thus he proved that the bodily changes which may occur due to environment won’t be passed to its offspring.

Question 4.
In a mango garden a farmer saw one mango tree with full of mango fruits but with a lot of pests. he also saw another mango tree without pests but with few mangoes. But the farmer wants the mango tree with full of mango fruits and pest free. Is it possible to create new mango tree which the farmer wants? Can you explain how it is possible?
Answer:

• It is possible to create new mango tree which one the farmer wanted with full of mango fruits and pest free.
• It is possible if he crosses a mango tree with full of mango fruits and pests with another mango tree without pests but with less mango fruits.
•  In F1 generation, he can get plants with full of mango fruits and without pests. Such plants are called hybrid plants.
• They can be self pollinated and desired plants can be selected from the mixed population of F2 generation.
• Otherwise, they can be vegetatively propagated to get these plants in a large number.

Question 5.
Explain monohybrid experiment with an example, which law of inheritance can we understand? Explain.
Answer:

• Cross pollinating a pure breed of tall (TT) and dwarf (tt) plants gave, F1 generation in which all the plants are heterozygous tall.

• These plants on self pollination gave F2 generation in which 75% of plants are tall and 25% of plants are dwarf.
• Out of 75% tall plants 25% of plants are homozygous tall (TT) and remaining 50% are heterozygous tall (Tt, tT).
• The remaining 25% dwarf plants are homozygous dwarf (tt).

• So the phenotype ratio in F, generation is 3: 1, whereas genotype ratio is 1: 2: 1.
• These plants on self pollination gave F3 generation, where a set of 25% tall plants gave only tall plants, rest of the tall plants gave 75% tall and 25% dwarf plants and a set of dwarf plants gave only dwarf plants.
• With this experiment we can understand two laws of inheritance. One is law of dominance and the second one is law of segregation.
• As only one trait is expressed in the offsprings of first generation crosses, we can assume that, among a pair of alleles for a character, only one expresses itself in the first generation one of the allele is dominant over the other. This is what Mendet called law of Dominance.
• The law of segregation states that every individual possesses a pair of alleles for any particular trait and that each parent passes a randomly selected copy (allele) of only one of these to its offspring.

Question 6.
What is the law of independent assortment? Explain with an example?
Answer:
1. In the inheritance of more than one pair of characters, the factors for each pair of characters assorts independently of the other pairs. This is known as “Law of independent assortment”.

2. When we cross two sets of ‘pure’ pea plants, one with yellow seeds with smooth skin and second is green seeds with wrinkled cover, in the F1 generation, we will get the seeds which are yellow and smooth. Each pea will now have factors YyRr.

3. On self pollination of these seeds we will get some seeds smooth yellow (YyRr or YYRR), some seeds smooth and green (yyRR or yyRr), some seeds were wrinkled and yellow (Yyrr or Yyrr) and some seeds were wrinkled and green (yyrr).

4. In the above, dihybrid cross parents produced offspring containing the actors of characters of yellow (YY), round (RR), and wrinkled (rr), green (yy) appeared independently mixing with each other in F generation.

5. RRYY, RRYy, RrYY, Rr Yy, RRYy, RrYY, RrYy, RrYy and RrYy are round and yellow.

6. RRyy, Rryy, Rryy are round and green.

7. rrYy, rrYy, rrYY are wrinkled and yellow.

8. rryy are wrinkled and green.

9. From the above results it can be concluded that the factors for each character or trait remains separate and maintains its identity in the gametes.

10. The factors are independent to each other passes to its offspring. This shows the “Law of independent assortment”.

Question 7.
Explain the Darwin’s theory of evolution ‘Natural selection’ with an example?
Answer:

• Darwin proposed the theory of “Natural selection”, means nature only selects or decides which organism should survive or perish in nature.
• The organisms with useful traits will survive, and the organisms having harmful traits are going to be perished or eliminated from its environment.
• Let us consider group of beetles that live in bushes on green leaves.
• Their population will grow by sexual reproduction. So they generate variations in their population.
• Let us assume crows eat these red beetles. if the crows eat more red beetles their population slowly reduces.
• Let us consider one colour variation arises during reproduction so that there is a beetle that is green in colour instead of red.
• Moreover this green colour beetle passes its colour to its offspring, so that all its progeny are green.
• Crows cannot see the green coloured beetles on green leaves of the bushes and therefore crows cannot eat them.
• But crows can see the red beetles and eat them, as a result there are more and more green beetles than red ones which decrease in their number.
• The variation of colour of beetle “green” gave a survival advantage to “green beetles” than red beetles. In other words it was naturally selected.

Question 8.
What are variations? Explain with a suitable example.
Answer:

• Differences in characters within very closely related groups of organisms are referred to as variations.
• Often a new character in a group may lead to variations that are inherited.
• If we observe parents and offsprings, there will be some similar features in the offspring of the parents.
• At the same time we find differences between parents and offspring in their features.
• These differences are an example of variations.
• Variations are quite apparent among closely related groups of organisms.
• If we take roses as an another example, we observe number of varieties in them.
• But we can still find some characters similar to all plants.
• Thus rose plants have similar physical features, at the same time they have differences in characters like flower colour, number of petals, leaf size, stem, spines, etc.
• These differences in features are variations.

Question 9.
What variations generally have you observed in the species of cow?
Answer:
In the species of cow the following contrasting variations can be observed:

• White coloured — spotted
• Long horns — short horns
• Height (tall) — dwarf
• Long tail — short tail
• Elongated face — stunted face
• More milk giving — less milk giving, etc.

Question 10.
What are the characters Mendel selected for his experiments on pea plant’?
Answer:
Mendel selected the following seven characters for his experiments on pea plant:

• Flower colour — Purple and White
• Flower position — Axil and Terminal
• Seed colour — Yellow and Green
• Seed shape — Round and Wrinkled
• Pod shape — Inflated and Constricted
• Pod colour — Green and Yellow
• Stem length — Tall and Dwarf

Question 11.
In what way Mendel used the word ‘Traits’- explain with an example.
Answer:

• Trait is a separate variant of an organism.
• Mendel hypothesized that characters were carried as traits.’
• An organism always carried a pair of factors for a character.
• He also hypothesized that distinguishing traits of the same character were present in the population of an organism.
• He assumed that the traits shown by the pea plants must be in the seeds that produce them.
• The seeds must have obtained these traits from the parent plants.
• The factors which are responsible for character or trait of an organism, are now named as “genes”.
• By all these we can assume that Mendel used the word ‘traits’ for indicating the variant of an organism expressed by a pair of factors or genes.
• For example, height is a character of pea plant while the tallness is a trait expressed by a pair of factors either vr or Tt and dwarfness is another trait expressed by a pair of factors tt.

Question 12.
What differences Mendel identified between parent and F2 generation.
Answer:
Mendel identified the following differences between parent and F2 generation.

 Parent F2 Generation 1. They are pure breeds. 1. They consist of mixed population. 2. They consist of homozygous alleles. 2. They consist of homozygous alleles in some plants and heterozygous alleles in some other plants. 3. They have some fixed characteristic features. 3. New combination of characters will appear.

Question 13.
Male is responsible for sex determination of baby – do you agree? If so write your answer with a flow chari
Answer:
I agree with the statement that male is responsible for sex determination of baby.

• There are two types of sex chromosomes in human beings, one is ‘X’ and other is ‘Y’.
• Females have two ‘X’ chromosomes in their cells (XX) whereas males have one ‘X’ and one ‘Y’ chromosomes in their cells (XY).
• All the gametes produced by woman (ovum) will be with only X chromosomes.
• The gametes produced by man (sperm) will be of two types one with X chromosomes and other Y chromosomes.
• If the sperm carries X chromosome and fertilizes the ovum, the resultant baby will have XX condition. So the baby will be a gril.
• II the sperm carries Y chromosome and fertilizes the ovuni, the resultant baby will have XY condition. So the baby will be a boy.
• So the gamete produced by the male is the deciding factor for sex determination of the baby.

Question 14.
Write a brief note on analogous organs.
Answer:

• The organs which are structurally different but functionally similar are known as ‘Analogous organs’.
• Wings of birds and bats are the examples for analogous organs.
• The wings of bats are skin folds stretched mainly between elongated fingers.
• But the wings of birds are a feathery covering all along the arm.
• The designs of the two wings, their structure and components are different.
• They look similar because they have common use for flying, but their origins are not common.
• This makes the ‘analogous’ characteristics.
• This type of evolution is called convergent evolution.

Question 15.
How do scientists utilise the information about fossils?
Answer:

• Fossils are evidence of ancient life forms or ancient habitats which have been preserved by natural processes.
• The scientific study of fossils is called ‘Paleontology’.
• Scientists utilise information about fossils to understand the evolutionary history of life.
• This information is also useful to study ecology and environmental history such as ancient climates.
• This also helps to find out how old that certain layer of earth is.
• This information is also utilized as indicators of possible fossil fuel deposits which are of great interest to humanity.
• Thus scientists utilize the information on fossils to learn more about the earth’s past.

Question 16.
Mendel selected a pea plant for his experiments. Mention the reasons in your point of view.
Answer:
Mendel selected pea plant for his experiments because

• Pea plants have short life cycle, they reproduce fast and mature right away.
• They exhibit seven pairs of contrasting characters which are easily recognizable such as smooth or wrinkled seeds, short or tall, height, etc.
• Hybrids and their offspring are fertile, that is continuous cross and self fertilizations were possible.
• They are highly naturally self pollinated because the reproductive parts of the flower are covered by the keel (petals) which only opens after pollination has been completed.
• Although the cross pollination methods are somewhat complicated, the results are largely successful.
• These plants are easy to grow either on the ground or its pots.
• These plants have short maturity and can produce large number of seeds in a single generation.

Question 17.
If the theory of inheritance of acquired characters proposed by Lamark was true how will the world be?
Answer:
If the theory of inheritance of acquired characters proposed by Lamarck was correct.

• All the organisms which lost some of their body parts should give birth to the offsprings without the lost parts.
• Rat which lost their tail should give birth to tail less rats.
• A handicapped who lost their legs in an accident should give birth to babies without legs.
• Women having holes in ears, should give birth to babies with holes in their ears.
• A body builder’s children should be body builders.
• But all these are not happening because bodily changes won’t be passed to its offspring.

Question 18.
Collect information on the inherited traits in your family members and write a note on it.
Answer:

• My grandfather and father had curling hair. too have curling hair. So it’s an inherited trait in family.
• My mother and me both have long noses which appear similar. It’s another inherited trait.
• Eyes of my grandmother, my brother and mine are similar, it’s another inherited trait.
• Ear lobes of my father, brother and mine are similar. This is another inherited trait.

Question 19.
Observe flowering plants in your surroundings? Write similarties and differences between them?
Answer:
The flowering plants in my surroundings are sun flower and Dandelion.
Similarites:

 Sun flower Dandelion 1. Growing conditions of sunlight 2. Best time to plant 3. Kingdom 4. Subkingdom 5. Division 6. Order 7. Class 8. Family Full sun Spring Plantae Trac heobionta Magnoliophyta Asterales Magnoliopsida Asteraceae Full sun Spring Plantae Tracheobionta Magnollophyta Asterales Magnoliopsida Asteraceae

Question 20.
With the help of given information write your corninent on evidences of evolution. Mammals have four limbs as do birds, reptiles and amphibians. The basic structure of the limbs is similar, though it has been modified to perform different functions.
Answer:

• The given information gives the evidences of evolution.
• Mammals, birds, reptiles and amphibians all these have forelimbs which have similar basic structure.
• But they are modified to perform different functions.
• The internal structure of forelimb of mammals such as whale, bat, horse, mole and man have common pattern in the arrangement of bones, even though their external form and functions are different.
• It indicates that all the vertebrates have evolved from a common ancestor. These organs are called homologous organs. This type of evolution is called divergent evolution.
• In case of bat (mammal) and bird the designs of the two wings, their structure and components are different.
• They look similar because they have common use for flying, but their origins are not common.
• These organs which are structurally different but functionally similar are known as ‘Analogous organs’. This type of evolution is called “convergent evolution”.
• There are remarkable similarities in the embryos of above mentioned animals even in their limb formation. These are called embryological evidences.

Question 21.
Collect information about carbon dating method. Discuss with your physical science teacher.
Answer:

• Carbon dating is the method used to calculate the age of rocks, minerals or fossils.
• The breakdown of radioactive isotopes of certain elements such as carbon, uranium and potassium takes place at a known rate. So the age of rock or mineral containing isotopes can be calculated.
• Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material.
• The earth’s atmosphere contains various isotopes of carbon, roughly in constant proportions.
• These include the main stable isotope 12C and an unstable isotope 14C.
• Through photosynthesis, plants absorb both forms from carbon dioxide in the atmosphere.
• When an organism dies, it contains the standard ratio of 14C to D12C.
• But as the 14C decays with no possibility of replenishment, the proportion of carbon 14 decreases at a known constant rate.
• The time taken for it to reduce by half is known as the half-life of 14C, which is 5730.
• The measurement of the remaining proportion of 14C in organic matter thus gives an estimation of its age.
•  Formula to calculate how old a sample is by carbon – 14 dating is
$$t=\left[\frac{I_n\left(\frac{N_f}{N_0}\right)}{-0.693}\right] \times t_{1 / 2}$$
where I is the natural logarithm, is the percent of carbon – 14 in the sample. Compared to the amount in living tissue, – 0.693 is the rate of decay for C – 14, t1/2 is the half life of C – 14 (5,700 years).
• As the half life of carbon-14 is 5,700 years, it is useful for dating objects up to about 60,000 years old.

Question 22.
Draw a checker board show the law of independent assortment with a flow chart and explain the ratio.
Answer:

• The ratio is 9:3:3: 1.
• RRYY, RRYy, RrYy, RrYy, RRYy, RrYy, RrYy, RrYY and RrYy are round and yellow. (9)
• RRyy, Rryy, Rryy are round and green. (3)
• rrYY, rrYy, rrYy are wrinkled and yellow. (3)
• rryy are wrinkled and green. (1)

From the above result, it can be concluded that factors for each character or trait remains separate and maintains its identity in the gametes. Thus in inheritance of more than one pair of characters the factors for each pair of characters assorts independently of the other pairs. This is known as “Law of independent assortment”.

Question 23.
Explain the process to understand monohybrid cross of Mendel experiment with a checkerboard.
Answer:

Question 24.
Prepare a flow chart showing evolution of man through ages.
Answer:

Question 25.
Nature selects only desirable characters. Prepare a cartoon.
Answer:

Question 26.
What is your understanding about survival of the fittest. Give some situations or examples that you observe in your surroundings?
Answer:

• Nature favours only useful variations.
• Each species tends to produce large number of offspring.
• They compete with each other for food, space, mating and other species.
• In this struggle for existence only the fittest can survive.
• When cat tries to catch some rats, the rats which can run fast and hide in its hole card survive and which is slow can become prey for the cat. Same way in the forest those deers will survive which can run fast and escape from predators.
• When we spray some insecticide on insects, most of them will die hut few which can withstand that chemical will escape.
• When a pest attacks our garden plants. most of them may die but which can with stand the pest can survive.
• When the dog tries to catch chickens, the chickens which will run fast and escape can survive but the slower ones will become food for the dog.

Question 27.
Write a monologue on evolution of a man to perform a stage show on the theatre day in your school.
Answer:
Hai, I am human being. I am going to recall what had happened to me so far, how had evolved, simply my journey from my origIn to till now. Nearly 1.6 – 2.5 million years ago, during the gelasian pleistocene period, I used to wander in the forest, It is believed that, I evolved from apes, Then I was short and had disproportionately long arms like this.

I used tools made of stone flakes. I was not the master hunter and I had a less specialized diet. I used to communicate through glusters. Between 1-1.8 million years ago, I gradually evolved into Homo erectus. I lived in this stage throughout most of the pleistocene. I used more diverse and sophisticated stone tools than my predecessors and it is believed that I travelled over oceans using rafts.

There was some possible evidence for that I had used fire. But my food was mostly raw meat and nuts, berries, fruits without cooking. Then I was not capable of producing sounds comparable to modern human speech. So I used to communicate through proto-language.

Around 1,00,000 – 40,000 thousand years ago I evolved into Homo sapiens neanderthalensis. I was stronger than present in those days. I was known for my large cranial capacity. I made advanced tools. I had language to communicate, and lived in complex social groups. I built my dwellings using animal bones.

I was largely carnivore and apex predator but I had cooked vegetables also in my diet. My genes then matched nearly. At this stage I was more closely related to modern human being differing in DNA by only 0.15%. Around 10 thousand years ago, I reached the present form of human being, the modern humans known as homosapiens. I learnt cultivation, Construction of houses, cooking, etc.

I had invented various things that help me to live comfortably. I civilised and learnt leading a social life with family system. With the help of my wisdom, I had reached the top most position among the all living beings controlling the total biosphere. Certain activities of mine are causing great harm to the nature also. But till today, I am the master of the world.

But my journey did not stop. It is still continuing. Let us see what may happen? Where can I reach ? What changes may come in me ? Hope for the best.
Thank you.

Fill in the blanks

1. The process of acquiring characters or traits is called ……………
2. Mendel’s experiment explains about …………..
3. The four characters observed in the experiments on law of independent assortment are …………..
4. If we cross pollinate red flower plant with white flower we will get percent of recessive trait plants.
5. TT or YY, Tt or Yy are responsible for a ………….. character.
6. Humans have ……………. pairs of autosomes and …………….. pair of sex chromosomes.
7. The population grows in …………. progression whereas food sources grow in …………… progression.
8. A goat which can’t walk properly can’t live for a long time. According to Darwin, this represents ………………….
9. Forelimb of whale is for swimming whereas in horse it is used for …………..
10. The study of fossils is called …………..
Answer:
1. evolution
2. heredity
3. Round, wrinkled, yellow, green
4. 100
5. dominant
6. 22, one pair
7. geometrical, arithmetic
8. survival of the fittest
9. running
10. palaeontology

Choose the correct answer:

Question 1.
Which of the following is not a variation in rose plant?
A. Coloured petals
B. Spines
C. Tendrils
D. Leaf margin
Answer:
C. Tendrils

Question 2.
According to Mendel, alleles have the following character.
A. Pair of genes
B. Responsible for character
C. Production of Gametes
D. Recessive factors
Answer:
A. Pair of genes

Question 3.
Natural selection means
A. Nature selects desirable characters
B. Nature rejects undesirable characters
C. Nature reacts with an organism
D. A, B
Answer:
D. A, B

Question 4.
Palaeoutologists deal with ………..
A. Embryological evidences
B. Fossil evidences
C. Vestigial organ evidences
D. All
Answer:
B. Fossil evidences

### TS 10th Class Biology 8th Lesson Heredity and Evolution Intext Questions

1 Mark Question and Answers :

Question 1.
What will happen if the sperm containing X chromosomes fertilizes the ovum?
Answer:

• All the ovum produced by women have only X chromosomes.
• So if the sperm containing X chromosomes fertilizes the ovum, the baby will have XX condition.
• So the baby will be a girl.

Question 2.
Were all your traits similar to that of your parents?
Answer:

• No, all my traits are not similar to my parents.
• There are certain traits which differ from my parents.
• This is due to genetical recombination during reproduction.

Question 3.
Does the embryological evidences indicate that frogs have evolved from ancestors of lslz?
Answer:

• Tadpole of frog resembles more the fish than the frog.
• It indicates that frogs have evolved from fish ancestors.

Question 4.
Does the life history of every individual exhibit the structural features of its ancestors?
Answer:

• There are remarkable similarities in the embryos of different animals from fish to man.
• The resemblance is so close at an early stage.
• This indicates that every individual exhibits the structural features of its ancestors.

2 Mark Question and Answers :

Question 1.
Is variation all about apparent differences ? or is it about some subtle differences as well that we most often overlook?
Answer:

• Variations are no4 always apparent differences.
• Sometimes these may be subtle differences that we most often overlook.
• When these subtle differences accumulate together they may become apparent.

Question 2.
How do parent plants pass on their traits to the seeds?
Answer:

• Every character or trait is controlled by a pair of factors called genes.
• At the time of sexual reproduction one facto, or each trait will pass to the ganetes.
• By the fusion of male and female gametes zygote will form in which factors from both male and female parents get paired again.
• This zygote will develop into seed in the later stages.
• Thus parent plants pass on their traits to the seeds.

Question 3.
Will the seeds from tall plants always produce new tall plants?
Answer:

• No. Tall plants may or may nut produce tail plants again.
• ibis is because tallness Is a dominant character in most of the plants especially in peas.
• So tail plant may be homozygous tall (iT) or heterozygous tall (TI).
• If the parental plant Is homozygous tall (pure breed), then they always produce new tall plants.
• If the parental plant Is heterozygoux tall plant, then they produce the tail and dwarf plants In the ratio of 3 1.

Question 4.
Who decides the sex of the baby – mother or father?
Answer:

• Sex determination of the baby depends on the sex chromosome carried by the sperm, as the ovum always carries X chromosome only.
• If the sperm with X chromosome fuses with ovum, the baby will have XX condition. So ‘he baby will be a girl.
• If the sperm with Y chromosome fuses with ovum, the baby will have XY condition. So the baby will be a boy.
• So the sperms that come from father decides the sex of the baby.
• In fact It is by mere chance and the chance for any sex formation is 50% as the male produces both sperms with X spernis with Y are produced in saine number.

Question 5.
How does the evolution of organisms take place7
Answer:

• Variations which are beneficial are selected by the nature and passed from parents to of spring through heredity.
• The saine process happens with every new generation until the variation becomes common feature.
• As the environment changes the organism within environment adapts and changes to the new living conditions.
• Over a long period of time, each species of organisms can accumulate so many changes that it becomes a new species.
• Thus evolution of organisms took place from common pre-existing ancestors.

Question 6.
Think why ancient human beings travelled from one place to other and how they travelled.
Answer:

• Ancient human beings travelled from one place to other in search of better living conditions such as availability of food, water and other facilities.
• They did not travel in a single line.
• They went forwards and backwards with groups, sometimes separating from each other.
• This travel is responsible for the formation of races.

4 Mark Question and Answers :

Question 1.
How does evolution take place?
Answer:

• Evolution takes place through the accumulation of new characters or variations in a species of organisms.
• AccumulatIon of variations occurs only when new characters are passed on from one generation to other and much more new characters are added to the pre-existing once.
• So this happens over a long period of time, sometimes several generations may pass.
• Hence it happens in a slow and steady manner.
• It is not just about change but producing something new and different.
• It is about the formation of new species and their adaptation to their environments.

Question 2.
Is the sex also a character or trait ? Does it follow Mendel’s law of dominance?
Answer:

• Yes, sex is also a character or a trait.
• It has two contrasting characters male and female.
• Male character is represented by a pair of allosomes XY’ (heterozygous).
• In this, we can consider Y as dominant and X as recessive.
• In this, recessive character is expressed only when it is homozygous recessive. i.e. female.
• Homozygous dominant is not existing as reproduction occurs between male (heterozygous dominant XY) and female (homozygous recessive XX) only.
• As X is not exhibiting its nature when Y is present along with it, it follows Mendel’s law of dominance.

Question 3.
Are birds and bats more closely related to each other than to squirrels or lizards?
Answer:

• No, bats are mammals whereas birds belong to aves.
• Squirrels are mammals and lizards are reptiles.
• So bats are more closely related to squirrels and lizards than birds.
• But bats and birds resemble more as they have wings.
• These wings are structurally different but functionally similar formed to have a common use of flying.
• But their origin is not common, so not closely related.
• These type of organs are called Analogous organs.
• This type of evolution is called Convergent evolution.

### TS 10th Class Biology 8th Lesson Heredity and Evolution Activities

Activity – 1.

Think of your own family, what simüa rifles do you share with your father and mother?
OR
Draw a table to represent the similarities of some characters like colour of eye(cornea), colour of hair, shape of nose, shape of face, type of earlobe (attached or free), inner thumb markings, etc. Write your characters in one column and that of your parents in the other columns.
Compare your traits with the traits of your parents, brother, sister and grandparents by drawing a table as gwen below In your note book.

Answer:

Q. Is there any character in you similar to that of your mother as well as your grandma?
Answer:
3 Characters:

• Colour of eye (Iris)
• Colour of hair
• Type of earlobe

Q. Is there any character in you similar only to that of your grandma?
Answer:
2 Characters:

• Shape of face
• Inner thumb marking

Q. How do you think these characters may have been inherited by you from grandma?
Answer:
Passing of characters or traits from parent to child.

Q. Is there any character that is not present in grandma but present in your mother and you ?
Answer:
2 Characters:

• Shape of nose
• Type of hair

Q. Think where from your mother got that character.
Answer:
This character is the result of inherited traits transmitted from parent to progeny.

Activity – 2.

Observe some of your friends and note their characters in the following table. Fill in yours as well.

Answer:

A. Compare your characters to that of any one of your friend. How many characters did you find were similar among you and your friend?
Answer:
Only few characters such as black hair and black eye were similar among me and my friend.

B. Do you share more similar characters with your parents or with your friends?
Answer:
I share more similar characters with my parents than my friends.

C. Do you think that your differences from parents are more or less than differences from friends? Why! Why not?
Answer:
My differences from parents are not same as differences from friend. This is because the differences from parents are subtle as there is more genetic relation with parents but the differences from friends are apparent.

Activity – 3.

Observe seeds in a pea or bean pod. You may observe several parts to arrive at a genera lisation.

A. Can you find two similar seeds there?
Answer:
No, all the seeds are not similar. They had certain variations.

B. What makes them vary?
Answer:

• They vary from one another because they are produced from different ovules.
• Ovules of a plant are female gametes.
• These gametes carry different factors (genes) for different characters randomly.

C. Why are variations important ?How are variations useful for an organism or a population?
Answer:

• Variations perhaps help a certain group of organisms in a community when conditions would otherwise be unfavourable for other groups.
• Desirable variations can be selected by nature.
• Desirable variations increase the chance of survival of an organism.
• Accumulation of variations after a long period leads to formation of new species.

Activity – 4.

Let us do the following activity to understand the
Mendelian principles of heredity.
Materials required:
a. 3 cm length and 1 cm breadth of chart strips – 4
b. 2 cm length and 1 cm breadth of chart strips – 4
c. Red buttons – 4
d. White buttons – 4
e. Chart, scale, sketch pen, pencil, 2 bags.

Method: Prepare a chart with 2 x 2 boxes along with number and symbol as shown in the figure.

Game 1 : Monohybrid cross (starting with hybrid parents)

To start with take 1,2 or 3,4 . In case you start 1,2 pick all the 16 long and short pieces and prepare such pairs in each of which you have a long and short piece. Take 4 pairs each of long and short strips and put them in two separate bags. Now each bag contains 4 strips (2 long and 2 short).One bag say ‘A’ represents male and the bag ‘B’ represents female.

Now randomly pick one strip each from bag A and B and put them together n the 1 on the chart. Keep picking out the strips and arrange them in the same manner till your bags are empty.

Same time your boxes in the chart are filled with pairs of strips. You might have got the following combinations, two long strips, one long and one short strip, two short strips.

A. What is the number of long strip pairs?
Answer:
There are four long strip pairs.

B. What is the number of one long and one short pairs?
Answer:
There are eight, one long and one short strip pairs.

C. What is the number of short strip pairs?
A. There are four short strip pairs.

D. What. is the percentage of each type ?Also find their ratios.
A. The percentage of long strip pairs, one long and one short strip pairs and short strip pairs are 25%, 50% and 25% respectively and the ratio is 1: 2: 1.

E. Whatcan you conclude fromthis game?
Aswer:
From this game I have concluded that:

• Every individual possesses a pair of alleles, for any particular trait.
• Each parent passes a randomly selected copy (allele) of these to an offspring.
• The offspring then receives its own pair of alleles for that trait one each from both parents.
• If the long strip is considered as dominant 75% exhibit dominant and 25% exhibit recessive character. Thus the phenotype ratio is 3: 1 in monohybrid cross.
• The genotype ratio is 1: 2: 1.

Activity – 5.

Observe the below diagram showing variation in beetle population and its impact.

Let us consider a group of twelve beetles. They live in bushes on green leaves. Their population will grow by sexual reproduction. So they were able to generate variations in population. Let us assume crows eat these red beetles. If the crows eat more Red beetles, their population is slowly reduced. Let us discuss the above 3 different situations in detail.
Answer:
Situation-1 : In this situation a colour variation arises during reproduction. So that there appears one beetle that is green in colour instead of red.

Moreover this green coloured beetle passes it’s colour to it’s offspring (Progeny).So that all its progeny are green. Crows cannot see the green coloured beetles on green leaves of the bushes and therefore crows cannot eat them, But crows can see the red beetles and eat them. As a result there are more and more green beetles than red ones which decrease in their numher.The variation of colour in beetle ‘green’ gave a survival advantage to green beetles’ than red beetles. In other words it was naturally selected. We can see that the ‘natural selection’ was exerted by the crows.

The more crows there are, the more red beetles would be eaten and the more number of green beetles in the population would be. Thus the natural selection is directing evolution in the beetle population. It results in adaptation in the beetle population to fit in their
environment better. Let us think of another situation.

Situation-2 : In this situation a colour variation occurs again in its progeny during reproduction, but now it results in blue’ colour beetles instead of ‘red’colour beetle. This blue colour beetle can lass its colour to its progeny. So that all its progeny are blue.

Crows can see blue coloured beetles on the green leaves of the bushes and the red ones as well. And therefore crows can eat both red and blue coloured beetles. In this case there is rio survival advantage for blue coloured beetles as we have seen in case of green coloured beetles. What happens initially in the population, there are a few blue beetles, but most are red. Imagine at this point an elephant comes by and stamps on the bushes where the beetles live. This kills most of the beetles. By chance the few beetles survived are mostly blue. Again the beetle population slowly increases. But in the beetle population most of them are in blue colour.

Thus sometimes accidents may also result in changes in certain characters of the population. Characters as we know are governed by genes. Thus there is change in the frequency of genes in small populations. This is known as ‘Genetic drift’, which provides diversity in the population.

Let us think of another situation:

Situation-3 : In this case beetles population is increasing, hut suddenly bushes were affected by a plant disease in which leaf material were destroyed or in which leaves are affected by this beetles got less food material.

Let us observe different stages of development of vertebrate embryos. Try to find out similarities and differences and discuss with your friends.
Answer:

• There are remarkable similarities in the embryos of different animals from fish to man.
• The resemblance is so close at an early stage.
• Gradually the similarities are decreased when they become babies.

Activity – 6.

Let us observe different stages of development of vertebrate embryos. Try to find out similarities and differences and discuss with your friends. (iMà
Answer:

• There are remarkable similarities in the embryos of different animals from fish to man.
• The resemblance ¡s so close at an early stage.
• Gradually the similarities are decreased when they become babies.

## TS 10th Class Biology Study Material 7th Lesson Coordination in Life Processes

Telangana SCERT 10th Class Biology Study Material Telangana 7th Lesson Coordination in Life Processes Textbook Questions and Answers.

## TS 10th Class Biology 7th Lesson Questions and Answers Telangana – Coordination in Life Processes

Question 1.
What do you mean by hunger pangs?
Answer:
Hunger pangs :

• Hunger pangs are the hunger contractions that occur in the stomach due to hunger generating signals that reach the brain from the stomach due to the secretion of hormone ‘Ghrelin’.
• Ghrelin is secreted from certain cells in the walls of the stomach.
• Increase in Ghrelin levels result in sensation of hunger and motivation to consume food.

Question 2.
What are the organ systems involved in digestion of food which we eat?
Answer:
The organ systems involved in digestion of food which we eat are endocrine system, nervous system, muscular system, circulatory system and excretory system.

Question 3.
Rafi said smell also increase our appetite can you support this statement. how?
Answer:
Yes, smell increases our appetite. However interactions between the senses of taste and smell enchance our appetite.

Question 4.
Write a note on peristalsis and sphincter function in stomach.
Answer:
A. Peristalsis:

• Peristalsis involves the contraction of the muscle behind the food and relaxation of the muscle infront of the food giving rise to a thrust that pushes the food forward through the digestive canal.
• A wave of contraction followed by relaxation ¡n muscles helps in forward movement of food in oesophagus.
• The wall of the oesophagus is made up of two kinds of smooth muscles.
• The inner layer consists of circular muscles and the outer layer of longitudinal muscles.
• Contraction of the circular muscles results in narrowing of the oesophagus just behind the bolus. So the food is squeezed downwards.
• Contraction of the longitudinal muscles infront of the bolus widen the tube, this result in shortening of that particular part of the oesophagus.
• Contraction and relaxation of these muscles bring in a wave-like motion that propels the food bolus into the stomach by the action called as peristalsis.
• Peristalsis is involuntary and under the control of autonomous nervous system.

B) Sphincters functions in stomach:

• Pyloric sphincter is present at the opening of stomach into the duodenum (small intestine).
• The pyloric sphincter squeezes only small quantities of food i.e., chyme into duodenum at a time.

Question 5.
Observe the given part of the digestive system. What is it? What is it’s role during digestion’?
Answer:

• It is large intestine present in human digestive system.
• In large intestine, water and mineral salts are absorbed.
• Faecal matter containing undigested food material, bile pigments and dead bacteria is formed in the large intestine.
• It is stored into the rectum of large intestine.

Question 6.
Give reasons.
a. If we press tongue against the palate we can recognise taste easily.
b. We can’t identify taste when food is very hot.
c. If glucose level falls in blood we feel hungry.
d. Small intestine is similar to a coiled pipe.
e. Urination increases when we take lot of fluids
f. The process of digestion goes on in a person whose central nervous system has been largerly affected
Answer:
a. Reason:

• When the tongue is pressed against the palate, the food substance is pressed against the opening of the taste bud letting it to reach the taste cells and triggering taste signals.
• Finally, the taste is recognized in the brain.

b. Reason:

• Most of the taste buds on the tongue are killed when the food is hot.
• This prevents the person identifying the taste.
• The perception of taste decreases when the temperature of the food rises beyond 35°C.
• But we don’t pay attention to It because we become worried about the burning feeling.

c. Reason:

• When glucose levels in the blood fall, we get hunger pangs in stomach.
• Hungry feeling start to occur in the stomach due to hunger generating signals that reach the brain from the stomach due to the secretion of the hormone ‘Ghrelin’.

d. Reason:

• Small intestine is coiled so as to fit in the human body.
• It is coiled to increase surface area and maximum nutrient absorption when food passes through it.

e. Reason:

• When we take lot of fluids, the kidneys will efficiently throw that water out by forming more urine than usual.
• When there is excess water in the body, the brain usually produces less of a hormone called vasopressin, which in turn causes the kidneys to produce a lot of dilute urine, until excess water is removed.

f. Reason:

• The enteric nervous system embedded in the walls of the long tube of our gut or alimentary canal control gut functions often independently of the brain.
• The mass of neural tissue of enteric nervous system filled with important neurotransmitters reveals that it does much more than merely handle digestion.

Question 7.
Write difference between the following.
a. bolus – chyme
b. small intestine – large intestine
c. mastication – rumination
d. propulsion – retropulsion
Answer:
a.

 Bolus Chyme 1. Food that is mashed in the mouth. 1. It is the repeatedly digested food in the stomach. 2. Alkaline in nature. 2. Acidic in nature. 3. Teeth and saliva turn food into bolus. 3. Stomach digests food by peristalsis into chyme. 4. Soft round ball of food that has been cheWed. 4. It is the liquified part of food. 5. Food going from mouth to stomach. 5. Food going from stomach to small intestine.

b.

 Small intestine Large intestine 1. It is longer and has small width. 1. It is shorter and has broad width. 2. It is in between the stomach and 2. It is the last part of the digestive large intestine. system. 3. It helps in digestion and absorption. 3. It helps in reabsorption of food and elimination of wastes. 4. It absorbs carbohydrates, proteins, 4. It absorbs water, nutrients and fats, minerals and vitamins. salts. 5. It has three parts – duodenum, jejunum and ileum. 5. It has four parts – caecum, colon, rectum and anal canal.

c.

 Mastication Rumination 1. Grinding, chewing and shredding of food in the mouth by teeth is called mastication. 1. It is the chewing of food that come from a part near the stomach of the animal to its mouth. 2. Mastication occurs only one time in the oral cavity. 2. Rumination allows food to undergo mastication more than once. 3. This is also known as chewing the food. 3. This is also known as chewing the cud. 4. It makes the food particles to tiny particles. Does not involve nutrient absorption 4. It allows greater nutrients to be extracted and absorbed from the food particles. 5. It occurs in most of the animals (mammals), eg : Human being 5. It occurs only in ruminate animals, eg: Cow

d.

 Propulsion Retropulsion 1. It is a means of creating force leading to movement of food. 1. It is a situation in which some  thing (food) is pushed or forced backwards. 2. Peristaltic waves move food from one part to the other. 2. Small amount of chyme is pushed into duodenum, simultaneously forcing most of it back into the stomach.

Question 8.
How can you say that mouth is a munching machine?
Answer:

• The circular muscles of the mouth enable the food to be pushed into the oral cavity and to be moved around.
• The teeth grind, chew and shred the food by a process called mastication.
• The surface muscles of the jaw help in biting and chewing actions and moving the jaw. The jaw moves up, down, forward and backward during food mastication.
• The teeth hell) in cutting and grinding , while tongue movements evenly spread out the food and help in mixing it with saliva.
• The muscles of the mouth enable the food to be pushed in the oral cavity and to be moved around.
• Hence we can say that mouth is a munching machine.

Question 9.
What is mastication? Explain the role of different sets of teeth in this process.
Answer:
Mastication : Mastication or chewing is the process by which food is crushed and ground by teeth. It is the first stage in digestion process.

Role of different sets of teeth in mastication:

• There are four types of teeth in human beings. They are Incisors, Canines , Premolars and Molars each for a specific function.
• Incisors are eight in number and they help the food to bite Dentition or cut.
• Canines are four in number and these are used for tearing the food.
• Eight premolars are present in our mouth and they are used for chewing and grinding food.
• Molars are eight in number and they are also used for chewing and grinding food.

Question 10.
During the journey of food from mouth to stomach through oesophagus. How does muscular system coordinate in this process?
Answer:
Muscular movement in mouth:

• The muscular system coordinates the journey of food from mouth to stomach through oesophagus.
• The circular muscles of the mouth enable the food to be pushed into the oral cavity and to be moved around.
• The surface muscles of the jaw help in biting and chewing actions.
• The wall of the oesophagus is made up of two kinds of smooth muscles.
• The inner layer consists of circular muscles and the outer layer of longitudinal muscles.
• Contraction and relaxation of circular and longitudinal muscles bring in a wave like motion that propels the food into stomach by the action called as peristalsis.
• Peristalsis is involuntary and under the control of autonomous nervous system.
• The muscle of the upper part of stomach relaxes to accept large volumes of swallowed food. Thus muscular system in mouth and oesophagus helps the food to reach from mouth to stomach through oesophagus.

Question 11.
Is there any reason for the intestine to be coiled with many folds? In what way it is helpful during the process of digestion?
Answer:

• The coiled and folded nature of intestine slows down the passage of food along the intestine and afford an increased surface for absorption.
• It also increases the surface area for intestine to increase the absorption of nutrients.
• The folded and coiled intestine absorbs nutrients and water more than they breakdown.

Question 12.
What is the function of peristalsis in these parts?
a. oesophagus
b. stomach
c. small intestine
d. large intestine
Answer:
a. Oesophagus: Peristalsis helps in pushing the food, down the oesophagus into the stomach.

b. Stomach:

• Peristalsis helps in storing food, breaking down food down and mixing it with juices secreted by stomach lining.
• Peristalsis in stomach helps in partial digestion of food called chyme.

c. Small intestine:

• Peristalsis pushes the digesting food through small intestine.
• It helps to mix the chyme to help in the digestive process.
• Peristalsis also helps in absorbing nutrients from the digesting food into the blood.

d. Large Intestine: Peristaltic movements help to propel feces along the large intestine through colon, to the rectum for expulsion from the body.

Question 13.
How can you justify the enteric nervous system as the second brain of the gut?
Answer:

• Enteric nervous system, the second brain consists of sheaths of neurons embedded in the walls of the long tube of our gut, or alimentary canal.
• The second brain measures about nine meters end to end from the oesophagus to the anus.
• The second brain contains some loo million neurons, mote than in either the spinal cord or the peripheral nervous system.
• This multitude of neurons in the enteric nervous system enables us to “feel the inner world of our gut and its contents.
• Enteric nervous system contains mass of neural tissue filled with important neurotransmitters.
• This reveals that it does much more than merely handle digestion or inflict the occasional nervous pang of hunger.
• Enteríc nervous system stimulates and coordinates the breaking down of food, absorbing nutrients and expelling of waste.
• Thus equipped with its own reflexes and senses, the second brain can control several gut functions often independently of the brain.
• Several scientists also believe that the enteric nervous system is a way too complicated to have evolved only to make sure things move through and out of our gut smoothly.
• Hence we can justify that the enteric nervous system as the second brain of the gut.

Question 14.
Rajesh feels hungry upon seeing food. Sheela says no to food as she is not hungry. What makes Rajesh hungry and what suppresses Sheelas hunger?
Answer:

• Increase in ghrelin levels in the stomach of Rajesh results in sensation of hunger and motivation to consume food.
• Secretion of hormone ‘leptin’ in the stomach of Sheela suppresses hunger in her.

Question 15.
How are taste and smell related?
Answer:

• Taste and smell are intimately related.
• This dose relationship is most readily seen in how we perceive the flavours of food.
• Anyone with severe cough and cold cannot make out the difference in the taste of certain food items.
• Actually, what is really being affected is the flavour of the food or the combination of taste and smell.
• That is because not only the taste but also the food odours are being defected.
• Taste it self is focussed on distinguishing, Chemical that have a sweet. salty sour, bitter or umami taste.
• However interactions between the senses of taste and smell enhance our perceptions of the foods we eat.
• Smell of the food flavour gives a similar taste to food.

Question 16.
List out the sphincter muscles of the food canal you have observed and give a brief description?
Answer:
1.

• The sphincters that are present in the food canal are E.sophased sphincter. Cardiac sphincter, Pyloric Shiflter, Anal sphincter and Ileocecal value or sphincter
• Esophageal sphincter allows entry of bolus into the oesophagus. and also reduces back flow from the oesophagus to pharynx.

2. Cardiac sphincter is present where the oesophagus meets the stomach. From its location, almost directly in front of the heart.

3. Pyloric sphincter is Present at the opening called the pylorus, located at the end of the stomach, at the connection between stomach and small intestine.

4. Pyloric sphincter allows only small quantities of food into duodenum at a time.

5. Anal sphincter is located at the anus, which marks the end of the digestive tract.

6. The release of waste from the rectum is controlled partly, voluntarily by anal sphincter locate at the anus.

7. The ileocecal valve is a sphincter muscle situated at the junction of the small intestine (ileuin) and the large intestine (colon).

8. It’s critical function is to limit the reflex of colonie contents into the ileum.

Question 17.
What experiment should you perform to understand action of saliva on flour? Explain it’s procedure and apparatus that you followed.
Answer:

• If salivary ducts are closed, saliva will not released into the mouth. This causes pain and swelling of salivary glands.
• Due to this the food will not get moistened and makes chewing and swallowing of food very difficult.
• If salivary amylase do not act on large molecules of starch into small glucose molecules digestion of these will not he completed.

Question 18.
What happens if salivary ducts are closed?
Answer:

• If salivary ducts are closed, saliva will not released into the mouth. This causes pain and swelling of salivary glands.
• Due to this the food will not get moistened and makes chewing and swallowing of food very difficult.
• If salivary amylase do not act on large molecules of starch into small glucose molecules digestion of these will not be completed.

Question 19.
If size and shape of small intestine is like oesophagus what will happen?
Answer:

• If size and shape of small intestine is like oesophagus. It is very difficult digestion process which would take place in small intestine.Shape and Size of small intestine = Oesophagus
• For the complete digestion of the food to occur, it has to stay in alimentary canal for 3 to 4 hours.
• Otherwise digestion will not be completed and nutrients are not absorbed into blood in the small intestine.
• The tube-like nature of small intestine as that of oesophagus will not provide increased surface area for complete absorption of nutrients.

Question 20.
Prepare a questionnaire to understand nervous coordination in digestion process.
Answer:

• What is meant by autonomous nervous system?
• What are neurotransmitters?
• What is enteric nervous system or second brain?
• What is the length of the enteric nervous system?
• Where is the enteric nervous system present in our body?
• When part the nervous system can control several gut functions?
• Does the enteric nervous system function independent of the brain?
• What do scientists believe about enteric nervous system?
• How many number of neurons are present in enteric nervous system?
• Is enteric nervous system the seat of conscious thoughts or decision making?
• How does enteric nervous system help in the digestion of food in alimentary canal?

Question 21.
Suggest a simple experiment to prove the role of palate in recognizing taste.
Answer:
Experiment to prove the role of palate in recognizing taste:

Aim : To prove the role of palate in recognizing taste.

Apparatus: Sugar crystals, Stop watch.

Procedure:

• Place some sugar crystals on the tongue.
• Keep mouth opened and see that tongue does not touch the palate.
• Record the time from the moment we placed the crystals on the tongue till we get the taste by using stop watch.
• Now repeat the test by placing the sugar crystals on the tongue pressing it against the palate.
• Record the time for; placing sugar crystals to getting the taste.

Observation : From the above activity we know that taste can be identified easily when the tongue is pressed against the palate.

Result : We can easily identify the taste of the substance we can identify the taste of it in lesser time.

Question 22.
Collect information related to feeling hunger from your school library and prepare a note on it.
Answer:
1. Hunger is a sensation experienced when one feels the physiological need to eat food.

2. A healthy well- nourished individual can survive for weeks without food intake.

3. Hunger is also the most commonly used term to describe the condition of people who suffer from a chronic lack of sufficient food and constantly or frequently experience the physical sense of hunger.

4. When hunger contractions start to occur in the stomach, they are informally referred to as hunger pangs. Hunger pangs usually do not begin until 12 to 24 hours after the last ingestion of food.

5. A single hunger contraction lasts about 30 seconds, and pangs continue for about 30-45 minutes, then hunger subsides for around 30-150 minutes.

6. Emotional states may inhibit hunger contraction levels of hunger are increased by lower blood sugar levels, and are higher in diabetics.

7. The fluctuation of leptin and ghrelin hormone levels results in the motivation of an organism to consume food. Increasing levels of leptin result in a reduction of one’s motivation to eat. Low levels of leptin cause the release of a secondary hormone, ghrelin hich inturn initiates the feeling of hunger.

8. Some studies have suggested that an increased production of ghrelin may enhance appetite evoked by the sight of food, while an increase in stress may also influence the hormone’s production.

9. The brain uses to evaluate the contents of the gut through vagal nerve fibres that carry signals between the brain and the gastrointestinal tract.

10. Blood level of glucose. amino acids and fatty acids provide a constant flow of information to the brain that may be linked to regulating hunger and energy intake.

Question 23.
Draw the block diagram showing sensation of taste from food material to brain.
Answer:

Question 24.
Draw a neatly labled diagram showing a peristaltic movement in oesophagus. Explain the importance of mucus on the walls of food pipe.
Answer:

Importance of mucus on the walls of food pipe:

• The walls of the food pipe secrete a slippery substance called mucus.
• Mucus lubricates and protects the oesophageal walls from damage.
• This helps the food bolus to slide down easily into the stomach through oesophagus.

Question 25.
Draw a schematic diagram of villus in small intestine. Explain how digestive system coordinate with circulatory system.
Answer:
Coordination of digestive system with circulatory system:

• The digestive system breaks down the food into nutrients.
• The transfer of food particles from the digestive system to the circulatory system takes place at the inner lining of the small intestine, through millions of finger-like projections called villi, which contain a network of capillaries.
• The transfer of food particles is possible because of absorption.
• Circulatory system transports the nutrients to different cells of the body.

Question 26.
The mere smell or sight of food stimulates hunger. Describe the process through a neat diagram?
Answer:

• The mere smell even the mere sight of delicious food stimulates the hunger.
• When we smell, the air borne substances get dissolved in the watery film of nasal mucus.
• The chemoreceptors in nose are otherwise called olfactory receptors which trigger signals in the form of nerve impulses to the brain where smell is defected.
• The amount of the neurosecretory protein hormone ghrelin in the blood increases as a result of visual stimulation images of food.
• Hunger contractions start to occur in the stomach due to hunger generating signals that reach the brain.
• It is beleived that the diencephalon in fore brain and vagus nerve (10th cranial nerve) plays an important role in carrying these signals to brain.
• Hunger pangs continue up to 30-45 minutes.
• Increase in ghrelin levels results in sensation of hunger and motivation to consume food.

Question 27.
With the help of a diagram show the movement of food from mouth to the stomach. What muscles and nerves are involved in the movement of food and what is this action called as?
Answer:
Muscles involved in movement of food from mouth to stomach:

• Typical movement of the oesophagus, stomach and intestine is called peristalsis. The muscles of the mouth enable the food to be pushed in the oral cavity.
• The first major muscle movement occurs when food or liquid is swallowed. Once the swallowing begins, it becomes involuntary and proceeds under the control of nerves in the jaw.
• Contraction and relaxation of circular and longitudinal muscles in the oesophagus bring in a wave-like motion that propels the bolus into stomach by the action called peristalsis.
• As the food approaches the closed ring of pyloric sphincter the surrounding muscles relax and allow the food to pass.
• The muscles of the upper part of the stomach have to relax and accept large volumes of swallowed material.
• The lower part of the stomach mixes food, liquid and digestive juice by its muscle action.

Nerves Involved in the movement of food:

• The fifth cranial nerve has been found to control the movement of muscles in the jaw.
• Under the action of autonomous nervous system saliva is secreted to make chewing and swallowing easier.
• Peristalsis in oesophagus is also under the control of autonomous nervous system.
• When the food is in the oral cavity, the nerves in the cheek and tongue are stimulated and carry messages in the form of nerve impulses to the brain.
• These messages are transmitted from the brain to the wall of the stomach and stimulate the glands to produce gastric juice.

Question 28.
Prepare a cartoon on Pavlov’s experiment with a suitable caption.
Answer:

Question 29.
How do you appreciate stomach as a churning machine. How does this coordination go on?
Answer:

• The stomach acts like a washing machine, churning the food around to break it into even smaller pieces.
• Mechanical mixing of food in stomach occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall.
• This allows the mass of food to further mix with the digestive enzymes.
• Due to churning of food in stomach, a mixture that resembles thick cream called chyme is formed.
• Hence we can call stomach a churning machine.

Question 30.
There is a great variety in diversified life processes, express your feelings in the form of a poem.
Answer:

• Circulatory system: Functioning of body cells, nutrients and oxygen are required, circulation supply those for the oxidation needed.
• Respiratory system: Living all the day, is the problem of the gay, respiration is there for oxygen inhalation and carbon dioxide for exhalation.
• Digestive system: I eat whatever I like, you are there to digest, absorbing all the nutrients, supplying it to circulation.
• Nervous system: When I was empty with thoughts, you woke my thinking power, fills the gap for ever, makes me active ever.
• Excretory system: Whatever you ate, I decide its fate,throws out of the body as waste, won’t allow it to paste.
• Skeletal / Muscular / Integumentary system: You supports and protect my body, will fit the organs in their position, secrete of my body’s fitness where are you skeletal muscular systems.

Question 31.
Suggest any two important habitual actions to your friend while eating food, keeping in view of this chapter.
Answer:

• Masticate the food thoroughly in the mouth. Because the food ¡n the mouth has to be broken down into tiny pieces to increase the surface area for action of substances that aid in digestion.
• Do not swallow food without chewing properly or do not eat in hurry.
• Eat small quantities of food at regular intervals for efficient digestion and absorption of nutrients.
• Eat the food that emit good smell and has good taste to eat.

Fill in the blanks

1. 2:1:2:3 is the ratio of our dentition. Here I represents ………………
2. Large protein molecules are broken down in ………… of digestive track.
3. ……………… is the strong acid which is secreted during digestion.
4. Olfactory receptors present in ………… triggering signals to brain.
5. pH of saliva is ……… in nature.

6. Fill in the blanks with suitable words given below.

Fluctuations of hormone ……. (i) ……. levels results in sensation of hunger and motivation of consuming food. When you feel your stomach is full and there is no need of food any more. Another hormone …….(ii)……. that gets secreted suppresses hunger. When we take food into the mouth it has to be chewed thoroughly. For this purpose the …….(iii)……. muscles help in chewing actions, while the …….(iv)……. muscles of the jaw moves the jaw up,down forward and backward during food mastication. The …….(v)…….nerve controls the muscles of the jaw. Under the action of …….(vi)……. nervous system Saliva is released by the salivary glands moistens the food to make chewing and swallowing easier. The salivary …….(vii)……. in the saliva breaks down the starch into sugars. As a result of chewing the food is transported into the oesophagus by the action of swallowing which is coordinated by the swallowing centre in the ……. (viii) ……. and the ……. (ix) …….. The tongue which is gustatory recognizes the taste and …….(x)……. nerve plays an important role in sensation of taste.

Choose the right ones.
i. leptin, ghrelin, gastrin, secretin.
ii. ghrelin, leptin, secretin, gastrin.
iii. deep muscles, surface muscles, circu lar muscles, striated muscles.
iv. surface muscles, deep muscles, neck muscles, long muscles.
v. fifth cranial nerve, second cranial nerve, fifth facial nerve, spinal nerve.
vi. central nervous systems peripheral nervous system, autonomous nervous system.
vii. lipase, sucrase, galactase, amylase.
viii. medulla oblongata, cerebrum, 8th spinal nerve, cranial nerve, 7th cranial nerve.
ix. Pons varoli, brain stem, medulla oblongata, mid brain.
x. 6th cranial nerve, 5th cranial nerve, 10th cranial nerve, optic nerve.
Answer:
1. Canine
2. Stomach
3. HCL
4. Nose
5. Alkaline nature
6.
i. ghrelin
ii. leptin
iii. surface
iv. deep
v. fifth cranial,
vi. autonomous
vii. amylase
viii. medulla oblongata,
ix. brain stem,
x. fifth cranial.

Choose the correct answer:

Question 1.
In which of the following situation you can taste quickly?
A. Put sugar cristals on tongue
B. Put sugar solution on tongue
C. Press the tongue slowly against the palate
D. Swallow directly without grinding and shredding
Answer:
C. Press the tongue slowly against the palate

Question 2.
Peristalsis is because of ……..
A. Contractiqn of longitudinal muscles
B. Contraction of circular muscles
C. Under control of autonomous nervous system
D. Digestive secretions
Answer:
C. Under control of autonomous nervous system

Question 3.
Sphincter that helps in opening of stomach into duodenum ……….. [ J
A. Cardiac
B. Pyloric
C. Anal
D. Gastric
Answer:
B. Pyloric

Question 4.
Glucose and amino acids are absorbed through the following part of villus.
A. epithelial cells
B. blood capillary
C. lymphatic vessel
D. all
Answer:
A. epithelial cells

Question 5.
The region in brain portion that controls hunger signals ………..
A. medulla
B. diencephalon
C. cerebrum
D. mid brain
Answer:
B. diencephalon

Question 6.
Human organism is an internal combustion machine because of ………
A. assimilation of energy from food
B. liberate CO2 during respiration
C. expel waste food at the end state of digestion
D. secrete powerful digestive juices
Answer:
A. assimilation of energy from food

### TS 10th Class Biology 7th Lesson Coordination in Life Processes Intext Questions

1 Mark Question and Answers :

Question 1.
How do we know that we need food?
Answer:
When we feel hungry then we know that we need food.

Question 2.
What plays a major role to identify stale food?
Answer:
Smell or odour plays a major role to identify stale food.

Question 3.
If you are having a tasty dish, do you think the smell of It increases your appetite?
OR
Does the smell of tasty dish increase our appetite?
Answer:
Yes, the smell of tasty dish increases our appetite.

Question 4.
What are your observations after chewing cumin jeera, sound, potato and apple?
Answer:
If we chew cumin (jeera), sound, potato and apple we observe morder to taste the food material the food should dissolve in saliva.

Question 5.
Are there any other sensations that affect taste?
Answer:
Temperature (hotness), coldness are the sensations that affect taste.

Question 6.
What happens to your taste sensation while sipping hot milk or tea?
Answer:
We find something more tasty while we sipping hot milk or tea.

Question 7.
What do you think could be the range of temperature for us to relish food items?
Answer:
30°C to 35°C could be the range of temperature for us to relish food items.

Question 8.
Suppose your taste buds were affected, what would happen to your Interest in having food?
Answer:
If my taste buds were affected I cannot identify the taste of food and also loose interest in having food.

Question 9.
Does the level of saliva secretion increase due to presence of food in the mouth?
Answer:
Yes, the level of saliva increases due to presence of food in the mouth.

Question 10.
Can the process of chewing go on in the absence of saliva?
Answer:
Yes, the process of chewing go on in the absence of saliva. But it is very difficult to chew food and swallow it.

Question 11.
Does the saliva have any other roles to play?
Answer:
The enzyme present in saliva that is salivary amylase converts large molecules of carbohydrates into small molecules of sugar like maltose and dextrose.

Question 12.
What is the use of such an increase in surface area of food ?
Answer:
It helps in more surface area for the enzyme to act.

Question 13.
What about the nature of medium for salivary amylase to act on food component?
Answer:
The nature of medium for salivary amylase to act on food component is alkaline.

Question 14.
If we swallow food material directly without mastication, what will happen?
Answer:
If we swallow food material directly without mastication, the food will not get digest easily and completely.

Question 15.
Do you think the pH of our mouth changes?
Answer:
Yes, the pH of our mouth changes from acidic to alkaline by the release of saliva from salivary glands.

Question 16.
What are the different systems that contribute to the proper functioning of digestion in the mouth?
Answer:
Endocrine, muscular, nervous systems contribute to the proper functioning of digestion in the mouth.

Question 17.
After the digestive process in the mouth where does the food move to?
Answer:
After the digestion in the mouth the food move to oesophagus.

Question 18.
What are the systems that come into play for swallowing food?
Answer:
Skeletal system, nervous system and digestive systems come into play for swallowing food.

Question 19.
What does the schematic diagram tell us about the oesophagus?
Answer:
The schematic diagram of the oesophagus tell us about its structure, secretion and function.

Question 20.
What kind of the tube is oesophagus?
Answer:
Oesophagus is a muscular and elastic tube.

Question 21.
How does mucus help in passage of food?
Answer:
Mucus helps in lubricating and protecting the oesophageal wall and helps the bolus to slide down easily in the oesophagus.

Question 22.
What makes the movement of the food bolus in the oesophagus easy?
Answer:

• Mucus helps the food bolus to slide down easily.
• Peristalic movements of the walls of oesophagus also move the food bolus in the oesophagus.

Question 23.
Why do you think the stomach is structured like a bag rather than a tube like oesophagus?
OR
Why is stomach structured like a bag rather than like a tube?
Answer:

• The food taken has to remain in the stomach for a long time for proper digestion.
• If it was like a tube it would just pass down without undergoing much changes and cannot remain in the stomach for long time.

Question 24.
What sets such processes into action?
Answer:

• When the food is in the oral cavity, the nerves in the cheek and tongue are stimulated.
• These carry messages in the form of nerve impulses to the brain.
• These messages are transmitted from the brain through motor nerve, to the wall of the stomach, and stimulate the gastric glands to produce gastric juice.

Question 25.
What stimulates stomach muscle into action?
Answer:
The nervous system stimulates stomach muscle into action.

Question 26.
What causes the stomach to churn and mix the food?
Answer:
The contractions of the stomach muscles squeeze and mix the food with the acids and juices of the stomach.

Question 27.
Why should only a small quantity of food be passed from stomach to duodenum?
Answer:
For the complete digestion of chyme only small quantity of it be passed from stomach to duodenum.

Question 28.
What is involved in bringing about peristalsis?
Answer:
Contraction and relaxation of the muscles present in various parts of gut bring about peristalsis.

Question 29.
What is the direction of peristalsis (which end of the gut does it begin)?
Answer:
The direction of peristalsis is forward direction that is from mouth to anus.

Question 30.
What happens if the direction of peristaisis is reversed?
Answer:
If the direction of peristalsis is reversed the food present in the gut moves backwards.

Question 31.
Why do you think small intestine is long and coiled?
OR
Why is the small intestine long and coiled?
Answer:
The small intestine is long and coiled because it has to stay for more time for complete digestion and absorption.

Question 32.
What process is involved in this process of absorption?
Answer:
Selective absorption of nutrients to be absorbed by the vifli of small intestine is involved in absorption.

Question 33.
What is the relation between fin ger1ike structures and paper folds?
Answer:

• Finger-like structures increase the surface area.
• The space inside the paper folds is very much high. So area is increased.
• So increasing of the surface area is the relation between finger-like structures and paper folds.

Question 34.
What systems do you think are working together?
Answer:
The digestive system and circulatory system are working together.

Question 35.
Do you think those systems work together in the whole length of the digestive canal? Why/ Why not?
Answer:
No, these systems are not working together in the whole length of the digestive canal. The digested food material is absorbed only in the small intestine hut not else where in the gut.

Question 36.
Often you may have experienced that if you have tension for some reason you start having loose motions. What does this show us?
Answer:
If we are tensed for some reason the enteric nervous system or second brain looses control over the gut. Hence without our intervention loose motions occur.

Question 37.
What moves out of the gut?
Answer:
The indigested food material moves out of the gut.

Question 38.
Two major pathways of waste expulsion are shown above. Which of the two do you think happens exclusively through the gut?
Answer:
Undigested food matter is expelled ¡n the form of stool from gut.

Question 39.
What controls the exit of stools from the body?
Answer:
The two muscular layers present in the anal sphincter control the exist of stools from the body.

Question 40.
Do you think the control is voluntary? Why! Why not?
Answer:
Yes, the control is voluntary in adults and it is involuntary in infants.

Question 41.
Did we have a sphincter In any other part of the digestive canal? Where was it?
Answer:
Yes. We have a sphincter at the opening where stomach opens into duodenum (small intestine).

Question 42.
What is the fate of the digested substances that move into blood from the intestine?
Answer:
The digested substances reach each cell of the body through circulatory system. There it gets oxidised and release energy.

Question 43.
Where, is the energy stored?
Answer:
The energy is stored in the cells as ATP.

Question 44.
Which system do you think will remove the excess salts from our body?
Answer:
The excretory system remove the excess salts from our body.

2 Mark Question and Answers :

Question 1.
What do you think that would happen if the salivary glands do not function in our mouth?
Answer:

• If the salivary glands do not function in our mouth saliva will not release and the food do not get moistened and chewing it is difficult.
• The taste of the food cannot be identified.
• Carbohydrates in the food cannot be breakdown and changed to dextrose and maltose molecules.

Question 2.
What would be the path of salt removal from gut to the outside of our body?
Answer:

• The digested food containing salts will be absorbed into the blood stream in small intestine.
• The circulatory system supplies this to kidney through renal artery.
• In the kidney salts are filtered and sent out of the body along with urine.
• Some of the salts also supplied to the skin. They will be sent out of the body in the form of sweat.

### TS 10th Class Biology 7th Lesson Coordination in Life Processes Activities

Activity -1.

Observe the following table, identify and tick those options that you think makes you feel hungry.

i. What stimulates hunger?
Answer:
Smell of food, sight of food and need of food stimulates hunger.

ii. What would be the result of stimulation of hunger?
Answer:
Hunger pangs occur in the stomach.

iii. Which system do you think would send the signals to make us realize that we are hungry?
Answer:
Nervous system.

iv. Which part of nervous system controls the hunger pangs?
Answer:
Central nervous system (CNS) controls the hunger pangs.

v. What kinds of controls are exercised during sensation of hunger? Are they hormonal or neural or both?
Answer:
They are both hormonal and neural.

vi. Can you suggest any four systems Involved In the process of generating hunger sensation?
Answer:
Digestive system, Endocrine system, Circulatory system and Nervous system.

Activity -2.

Observation of how our taste is affected by the sense of smell.

• First close your nose with your fingers.
• Pop in some zeera in your mouth and chew it for sometime.
• After that chew sounf.
• Could you recognise the taste?
• How long it taken to know the taste?
• After sometime wash your mouth and repeat the activity by chewing a piece of an apple followed by a potato (remember to close your nose)

i. What are your perception about the taste?

• We can taste the food that is in the form of liquid only.
• Only after the dissolved food enters into the cup like taste buds, the sense of taste is carried to the brain for analysis. Then only we will know the taste of food material.
• Similarly of factory receptors which trigger signals in the form of nerve impulses to the brain where smell is detected.

ii. Could you feel the taste of both or did they taste the same? Why?
Answer:
No, because taste buds couldn’t send the taste signals to brain.

iii. What happens when we put food material in our mouth?
Answer:
Our mouth salivates.

iv. Name the parts in the mouth that help us to taste food.
Answer:
Papillae (taste buds), palate.

Activity -3.

1. Take a pinch of asafoetida powder/garlic and rub it on hand kerchief I tissue paper.
2. Close your eyes and smell it.
3. Then try to identify taste of different types of food materials with the help of your friend

i. Does garlic have a stronger scent than apple? How do you think the stronger scent affects your sensation of taste?
Answer:
Yes, garlic have a stronger scent than apple. The stronger scent motivates us to eat different types of foods.

ii. How many food materials have you identified correctly?
Answer:
Do the activity, write your own answer.

iii) Write a few lines on relation between smell and taste
Answer:

• Taste and smell are intimately entwined. This close relationship is most apparent in how we perceive the flavour of food.
• Taste itself is focussed on distinguishing chemicals that have sweet, salty, sour, bitter or umami taste.
• However interactions between the senses of taste and smell enhance our perceptions of the foods, we eat.

iv) Have you ever felt that a particular food is tasty just by looking at it ?
Answer:
I felt so many times. In general, we prefer the food material, which is attractive to our eyes and flavour to nose, then we taste it.

Activity – 4.

Role of different parts of the mouth in helping us to taste keeping sugar crystals over the tongue.

• Place some sugar crystals on the tongue and keep your mouth opened and see that your tongue dosen’t touch the palate.
• Record the time from the moment you placed the crystals on your tongue till you got the taste by using stop watch.
• Now repeat the test by placing the sugar crystals on the tongue and pressing it against the palate.
• Record the time from placing sugar crystals to getting the taste. Or put a drop of sugar solution on your tongue using a dropper.

Observation:

Based on the above activity we know that taste can be identified easily when the tongue is pressed against the palate.

i. Can we taste on dry tongue?
Answer:
No.

ii. Which way helped you taste faster? Why?
Answer:
Taste can be identified faster when the tongue is pressed against the palate. When the tongue is pressed against the palate the food substance is pressed against the opening of the taste bud letting it reach taste cells triggering taste signals. Finally, the taste is recognised in the brain.

Activity – 5.

To show breakdown of food by using the model of cha Ikpiece kept in vinegar

• Break a piece of chalk into two halves.
• Crush one half to tiny pieces leaving the other as it is.
• Take two small mineral water bottles (½ ltr bottle) cut them into two equal halves and discard the upper portion.
• Now we have two beakers from the lower cut portion.
• Fill them half with vinegar and add the crushed chalk to one beaker and the other uncrushed half chalk to the other.
• Observe them after half-an-hour or so.

i. Which one dissolved faster the crushed chalk or the whole one?
Answer:
Beaker with crushed chalk dissolved faster than the whole one. This experiment tells us the need of mechanical crushing of food increase surface area for action of substances that aid in digestion.

ii. How does this process of mechanical crushing go on In the mouth?
Answer:
Mechanical crushing of food goes in the mouth by chewing.

iii. Which parts in the mouth are involved in this?
Answer:
Teeth and tongue.

iv. What are the systems involved in this process?
Answer:
Digestive system, Nervous system, Muscular system.

Activity – 6.

Observe the diagram and answer the questions and fill in the table.

i. Observe the model or chart of jaw. On the basis of the figure, try to guess what could be the functions of molars?
Answer:
Chewing and grinding.

ii. What do you think could be the function
Answer:
Biting.

iii. Which set of teeth helps in grinding food?
Answer:
Premolars and molars.

iv. Which set helps in tearing food?
Answer:
Canines.

v. Write your dental formula.
Answer:
$$\frac{2,1,2,3}{2,1,2,3}$$

 Type of teeth Number of teeth in each jaw Shape Function Incisors 8 Chisel, sharp edges Biting Canines 4 Sharp, pointed edges Tearing Premolars 8 Diamond shape blunt and flat Chewing and grinding Molars 12 Rectangular, blunt and flat Chewing and grinding

Activity – 7.

Testing pH of mouth at Intervals of one hour.

• Collect a strip of pH paper with a colour chart from chemistry teacher.
• Take a small piece of the pH paper and touch it to your tongue.
• Match the colour with the colour chart and note the pH.
• Take some readings after having your food at lunch break.
• Compare your readings with that of your friend.
• Take atleast 4 readings.
 S.No. Name of the Student pH value before lunch pH value sifter lunch pH value sifter an hour pH value after 2 hrs 1. Sairam 2. Venkata Krishna 3. Yedukondalu 4. Sivaji 5. Manohar 6. Pavan Kumar

i. What is the usual range of pH of your mouth ? Acidic or basic?
Answer:
Acidic in nature.

ii. Did you observe any change In pH after eating? What may have caused the change?
Answer:
Yes, there is change in pH after eating. Saliva secreted causes the change.

iii. In what kind of pH do you think salivary amylase acts well?
Answer:
In Alkaline medium that is pH beyond 7.

iv. Does the type of food have any role to play on the pH of our mouth?
Answer:
No.
Based on the above tests we know that saliva secreted causes the medium to change to alkaline as it aids in action of enzyme, salivary amylase.

Activity – 8.

Making a model of oesophagus to observe how bolus moves forward.

• Take a piece of waste cycle tube and insert one or two potatoes into it.
• Lubricate the inner side of the tube with oil.
• In the same way smear oil over potatoes.
• Insert oil-coated potatoes in the tube.
• Now try to push the potatoes by squeezing the tube.

i. How do you squeeze the tube to make the potatoes pass through? How did the oil work?
Answer:
The cycle tube is held just above the place where the potatoes are and squeezed down. The oil works as a lubricant and allows the free movement of potato through the cycle tube.

ii. Do you think that the muscles in the wall of the oesophagus have to do something like this?
Answer:
Yes.

iii. How did oil help you in pushing the potatoes through the pipe?
Answer:
Oil acted as lubricant to push the potato easily in the forward direction.

How is the stomach protected from the secretions of its own acids?

• Take two similar green leaves.
• Grease one leaf with petroleum jelly, leave the other free.
• Add 1 or 2 drops of sorne weak acids on both the leaves.
• Observe them after half-an-hour or so and write your observations.

i. Which leaf was effected by the acid?
Answer:
The leaf to which petroleum jelly was not applied.

ii. What kind of change did you observe in the leaves?
Answer:
The colour of the leaf changes.

iii. What saved the other leaf from the effect of acid?
Answer:
Petroleum jelly.
From the above activity we can conclude that mucus secreted by the walls of stomach protect it from the harmful effects of hydrochloric acid.

Activity – 9.

Paper tube and folded papers

• Provide the students with a piece of paper.
• Let them calculate the area of one side of the paper and make a roll of it.
• Try to fill the tube by inserting few folded papers as much as possible in it.
• Pull out the papers from the tube, unfold them and find out the whole area of the papers.

i. Compare the area of the folded papers with that of the roll. Do you find any increase in the area? If so, try to find out the reasons.
Answer:
Area is increased. The space inside the folded papers is very much high. So we can insert as many folded papers as we could. From the above activity we can infer that the inner surface of the small intestine contains thousands of finger-like projections called villi which increase the surface area of absorption of nutrients in small intestine.