AP 10th Class Biology 13th Lesson Questions and Answers Our Environment

AP State Board new syllabus AP Board Solutions Class 10 Biology 13th Lesson Our Environment Questions and Answers.

10th Class Biology 13th Lesson Our Environment Questions and Answers

10th Class Biology 13th Lesson Questions and Answers (Exercise)

Question 1.
Which of the following groups contain only biodegradable items ?
a) Grass, flowers and leather
b) Grass, wood and plastic
c) Fruit – peels, cake and lime juice
d) Cake, wood and grass
Answer:
c) Fruit – peels, cake and lime juice

Question 2.
Which of the following constitute a food-chain ?
a) Grass, wheat and mango
b) Grass, goat and human
c) Goat, cow and elephant
d) Grass, fish and goat
Answer:
b) Grass, goat and human

Question 3.
Which of the following are environment-friendly practices ?
a) Carrying cloth-bags to put purchases in while shopping.
b) Switching off unnecessary lights and fans
c) Walking to school instead of getting your mother to drop you on her scooter
d) All of the above.
Answer:
d) All of the above.

Question 4.
What will happen if we kill all the organisms in one trophic level ?
Answer:
If we kill all the organisms in one trophic level.

• The transfer of food energy to the next level will stop.
• There will be overpopulation of individuals belonging to the previous trophic level.
• The organisms of higher trophic level will also die.
• Hence, it will result in imbalance in the ecosystem.

Question 5.
Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem ?
Answer:

• No, the impact of removing all the organisms in a trophic level will be the same for different trophic levels.
• No, the organisms of any trophic level cannot be removed without causing any damage to the ecosystem.

Question 6.
What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem ?
Answer:
Biological magnification: Biological magnification is the phenomenon in which harmful chemicals enter in the food chain and its concentration increases at each trophic level.
The levels of biological magnification are different at different levels of the ecosystem. It will be increased with each successive level.

Question 7.
What are the problems caused by the non-biodegradable wastes that we generate?
Answer:
Non-biodegradable wastes : These are the wastes, which cannot be dissolved or decomposed by natural agents such as micro-organisms and act as a pollution source.
Examples of non-biodegradable wastes are toxic chemicals, synthetic fibers, pesticides, plastics, etc.
The following are the problems resulting due to non-biodegradable wastes :

• Non-biodegradable wastes cause biomagnification as a result of this accumulation, they pollute soil and water; they pollute the environment. If such wastes are burned, they pollute the air.
• The wastes like pesticides, decline the fertility of the soil, with continuous application, the pH level of the soil turns unsuitable for vegetation.
• The pesticides also accumulate progressively at each trophic level and thus exhibit a harmful effect on the organisms.
• The wastes like plastic burning discharge toxic components into the surroundings resulting in, air pollution.
• The non-biodegradable wastes are the prime reasons for land, air, soil, and water pollution.

Question 8.
If all the waste we generate is biodegradable, will this have no impact on the environment ?
Answer:
Microorganisms and other abiotic elements work together to break down cortiplex substances into simple organic matters which finally suspend and disappear into the soil. The whole process is natural which can be fast or slow. So, the environmental issues and risks caused by biodegradable wastes are very low.

Question 9.
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage ?
Answer:
The ozone layer in the stratosphere absorbs a portion of the radiation from the sun, preventing it from reaching the planet’s surface. Most importantly, it absorbs the portion of UV light called UVB. UVB is a kind of ultraviolet light from the sun that has several harmful effects.

The damage to the ozone layer is a cause for concern because:

• It causes skin darkening, skin cancer, aging, and corneal cataracts in human beings.
• It can result in the death of many phytoplanktons that leads to increased global warming.

To limit the damage to the ozone layer.

• The release of CFCs (Chlorofluorocarbons) into the atmosphere must be reduced.
• CFCs used as refrigerants and in fire extinguishers should be replaced with environmentally- safe alternatives.
• Also, the release of CFCs through industrial activities should be controlled.

10th Class NS 13th Lesson Questions and Answers (InText)

Page No.110

Question 1.
What are trophic levels ? Give an example of a food chain and state the different trophic levels in it.
Answer:
Trophic levels:
The position, level, or position in a food web, a food chain, or an ecological pyramid is known as a trophic level.
The first trophic level is formed by the producers, as they produce food. The second trophic level is formed by the primary consumers.

The third trophic level is formed by the secondary consumers. The fourth trophic level is formed by the tertiary consumers. Example of a food chain:
Grass → Grasshopper → Frog → Snake → Eagle
Here producer is the grass, which is consumed by the grasshopper, that is the primary consumer.
The grasshopper is further consumed by the frog, that is, the secondary consumer. The frog is consumed by snake that is, the tertiary consumer. Lastly, the snake is eaten up by the eagle, that is, the top consumer.

Question 2.
What is the role of decomposers in the ecosystem ?
Answer:
Decomposers play a critical role in the flow of energy through an ecosystem. They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.

Decomposers:

• Decomposers in ecosystems act as environmental cleaners by decaying dead plants and animals.
• They aid in the recycling of nutrients and make the soil fertile.
• They make room for a new life in the biosphere by decaying the dead.
• They contribute to the reintroduction of different elements into moisture, soil and air for reuse by producers such as crop plants.

Page No. 112

Question 3.
Why are some substances biodegradable and some non-biodegradable ?
Answer:
Substances are classified as biodegradable and non-biodegradable because a few of them can be decomposed by microorganisms and some cannot.

• Biodegradable : Substances that are broken down by microorganisms like bacteria or fungi into simple organic substances are called biodegradable ex : vegetables leaves plant and animal products.
• Non-biodegradable : The substances that cannot be decomposed by microorganisms are known as non-biodegradable. Ex : Plastic, glass.

Question 4.
Give any two ways in which biodegradable substances would affect the environment.
Answer:

• Biodegradable substances are decomposed by the action of microorganisms and decomposed materials are recycled through a geo-chemical cycle.
• Biodegradable substances such as tree leaves, plant parts, and kitchen wastes can be used as humus after composting. This will enhance soil fertility.

Biodegradable substances can affect negatively on environment in following ways:

• They may produce a foul smell during the decomposition process.
• They may produce some harmful gasses such as ammonia, methane etc. which can further cause global warming.

Question 5.
Give any two ways in which non-biodegradable substances would affect the environment.
Answer:
Non-biodegradable substances affect the environment by :

• They contaminate soil and water resources as they cannot be decomposed by microorganisms.
• These substances, when accidentally eaten by stray animals, can harm them and can even cause their death.
• Those accumulating in nature causing pollution.
• They cause diseases.
• It also causes biological magnification.

Page No. 114

Question 6.
What is ozone and how does it affect any ecosystem ?
Answer:
Ozone is a gas made of three atoms of oxygen. Its formula is 03. It is a hazardous gas that is prevalent high up in the atmosphere.
Ozone is a vital gas for all sorts of ecosystems on earth as it protects the environment from the damaging effects of UV radiation causing skin cancer and cataract and impairs our immune system.

Question 7.
How can you help in reducing the problem of waste disposal ? Give any two methods.
Answer:
Eight Ways to Reduce Waste :

• Use a reusable bottle/cup for beverages on-the-go….
• Use reusable grocery bags, and not just for groceries
• Purchase wisely and recycle.
• Avoid single-use food and drink containers and utensils.
• Buy second hand items and donate used goods.
• Compost it!
• Shop local farmers markets and buy in bulk to reduce packaging.
• Minimize your use of paper: use e-paper as mail, receipts, magazines.

AP Board Solutions Class 10 Biology Chapter 13 Questions and Answers (Lab Activities)

Activity – 13.1

• You might have seen an aquarium. Let us try to design one.
• What are the things that we need to keep in mind when we create an aquarium? The fish would need a free space for swimming (it could be a large jar), water, oxygen and food.
• We can provide oxygen through an oxygen pump (aerator) and fish food which is available in the market.

Question 1.
If we add a few aquatic plants and animals it can become a self-sustaining system. Can you think of how this happens ?
Answer:
The gas oxygen released by plants is used by animals and releases the carbon dioxide that is absorbed by plants. And animal excursions are also utilized by plants so the aquarium becomes a sustaining system.
An aquarium is an example of a human-made ecosystem.

Question 2.
Can we leave the aquarium as such after we set it up ?
Answer:
No, we can’t leave the aquarium after setting it up. It must be cleaned frequently.

Question 3.
Why does it have to be cleaned once in a while ?
Answer:
Without plants aquarium is not a sustaining system,fish excretion pollute the water and must be cleaned.

Question 4.
Do we have to clean ponds or lakes in the same manner ? Why or why not ?
Answer:
No ponds and lakes are sustaining systems.
They have both plants and animals which depend on each to make it sustainable .

Activity – 13.2

Question 1.
While creating an aquarium did you take care not to put an aquatic animal which would eat others ? What would have happened otherwise ?
Answer:
If The aquatic animals would eat each other some animals would die and it would imbalance the food chain. Later top consumers also die due to lack of food.

Question 2.
Make groups and discuss how each of the above groups of organisms are dependent on each other.
Answer:

• In any food chain each organism depends on previous trophic level.
• In this link damage of any trophic level effect on other level.
• It collapse the sustainability of ecosystem.

Question 3.
Write the aquatic organisms in order of who eats whom and form a chain of at least three steps.
Answer:
Aquatic plants → Insect larvae → Small fish → Big fish

Question 4.
Would you consider any one group of organisms to be of primary importance? Why or why not ?
Answer:

• I can’t consider any one group of organisms to be of primary importance,because any organism or group does not survive individually.
• Even the plants known as producers do not survive without animals. So we can’t consider one group of organisms to be of primary importance.

Activity – 13.3

• Newspaper reports about pesticide levels in ready-made food items are often seen these days, and some states have banned these products. Debate in groups the need for such bans.

Question 1.
What do you think would be the source of pesticides in these food items ? Could pesticides get into our bodies from this source through other food products too ?
Answer:
Pesticides can enter the food chain in many ways. When pesticides are sprayed on crops, and consumed as fodder by livestock, they can leave residue in animals. Similarly, when pesticides wash off with rainwater into streams can cause the planktons to absorb these into the system and in turn be eaten up by aquatic animals like fish, by eating them pesticides enter our body.

Question 2.
Discuss what methods could be applied to reduce our intake of pesticides.
Answer:
Buy local, organic produce whenever possible.

• When buying packaged products, look for those that contain organic ingredients- the more organic the better.
• Don’t limit your organic products to food alone – look for organic varieties of body . care products and clothing as well.
• PEELING and TRIMMING : Peel fruits and vegetables when possible to reduce dirt, bacteria, and pesticides.
• Use organic farming is the best way to avoid pesticides.

Activity – 13.4

Question 1.
Find out from the library, internet or newspaper reports, which chemicals are responsible for the depletion of the ozone layer.
Answer:
Ozone depleting substances are

• Chloro Fluoro Carbons (CFCs)
• Hydro Chloro Fluoro Carbons (HCFCs)
• Hydro Bromo Fluoro Carbons (HBFCs)
• Halons.
• Methyl Bromide.
• Carbon Tetrachloride.
• Methyl Chloroform.

Question 2.
Find out if the regulations put in place to control the emission of these chemicals have succeeded in reducing the damage to the ozone layer. Has the size of the hole in the ozone layer changed in recent years?
Answer:

• The ozone layer – the portion of the stratosphere that protects our planet from the Sun’s ultraviolet rays  thins to form an “ozone hole” above the South Pole,
• Yes it has been decreasing through the past two decades. The elimination of ozone- depleting substances through the Montreal Protocol is shrinking the hole. It’s really good news.

Activity – 13.5

• Collect waste material from your homes. This could include all the waste generated during a day, like kitchen waste (spoilt food, vegetable peels, used tea leaves, milk packets and empty cartons), waste paper, empty medicine bottles/strips/bubble packs, old and torn clothes and broken footwear.

a) Bury this material in a pit in the school garden or if there is no space available, you
can collect the material in an old bucket/ flower pot and cover it with at least 15 cm of soil.
b) Keep this material moist and observe at 15-day intervals.

Question 1.
What are the materials that remain unchanged over long periods of time?
Answer:
Footwear, fibers, metals, poisonous chemicals, pesticides, and consumer goods like disposable bags, supermarket bags, plastic containers, water bottles, and metal cans are unchanged over long periods of time.

Question 2.
What are the materials which change their form and structure over time?
Answer:

• Paper
• Food waste
• Human waste
• Manure
• Sewage sludge
• Slaughterhouse waste
• Dead animals and plants
• Hospital waste are change their form and structure over time.

Question 3.
Of these materials that are changed, which ones change the fastest ?
Answer:
Vegetable wastes and food wastes are change faster.

Activity – 13.6

Question 1.
Use the library or, internet to find out more about biodegradable and non- biodegradable substances.
Answer:
a. Biodegradable material generally includes wood, wool, cotton, animal waste or any other organic material which can be broken down into carbon dioxide, methane or any other simple organic molecules with the help of microorganisms. They are often referred to as ‘Bio-waste’.

b. Non-biodegradable materials are not easily affected by the natural process as they do not react with and dissolve in the soil easily. Some of these items that are common in day to day lives are plastic products, aluminum cans, bottles, metal scraps, glasses, grocery bags and Styrofoam (polystyrene)

Question 2.
How long are various non-biodegradable substances expected to last in our . environment ?
Answer:
Non-biodegradable waste examples include- plastics, metal, aluminum cans, tyres, pains, toxic chemicals, polystyrene, generally they take lakhs of years to decompose. These days, new types of plastics which are said to be biodegradable are available.

Question 3.
Find out more about such materials and whether they do or do not harm the environment.
Answer:

• A plastic is considered biodegradable if it can degrade into water, carbon dioxide, and biomass in a given time frame
  Types of Bioplastics are : Starch, Cellulose, Protein, Organic, Aliphatic Polyesters,
• Most of these bioplastics are degradable, so these are not harmful to the environment.

Activity – 13.7

Question 1.
Find out what happens to the waste generated at home. Is there a system in place to collect this waste ?
Answer:
Yes, in urban areas municipal corporations collect the garbage and in rural areas grama panchayats take this duty.

Question 2.
Find out how the local body (panchayat, municipal corporation, resident welfare association) deals with the waste. Are there mechanisms in place to treat the biodegradable and non-biodegradable wastes separately?
Answer:

• Yes they separate biodegradable waste and convert them into fertilizers,
• Non-biodegradable waste sent to recycle unit.

Question 3.
Calculate how much waste is generated at home in a day.
Answer:
Nearly 5 kg waste is formed from each home.

Question 4.
How much of this waste is biodegradable ?
Answer:
Among the 5 kg waste nearly 3 kg waste is biodegradable.

Question 5.
Calculate how much waste is generated in the classroom in a day.
Answer:
From the class room nearly 2 kg waste is formed.

Question 6.
How much of this waste is biodegradable ?
Answer:
Most of my class room waste is biodegradable because it’s almost paper waste.

Question 7.
Suggest ways of dealing with this waste.
Answer:

• We use decompose pit for biodegradable waste and prepare vermicompost.
• We prepare recycled paper from paper waste.
• Lot of decorated items are prepared from class room waste.

Activity – 13.8

Question 1.
Find out how the sewage in your locality is treated. Are there mechanisms in place to ensure that local water bodies are not polluted by untreated sewage?
Answer

• Sewage treatment is a type of waste water treatment which aims to remove contaminants from sewage to produce an effluent that is suitable to discharge to the surrounding environment.
• Wastewater is treated in 3 phases: primary (solid removal), secondary (bacterial decomposition), and tertiary (extra filtration).
• Primary treatment is the first phase of sewage treatment: wastewater is placed in a holding tank and solids settle to the bottom where they are collected and lighter substances like fats and oils are scraped off the top.
• Secondary treatment is where waste is broken down by aerobic bacteria incorporated into the wastewater treatment system.
• Tertiary treatment is designed to filter out nutrients and waste particles that might damage sensitive ecosystems; wastewater is passed through additional filtering lagoons or tanks to remove extra nutrients.
  By this wastewater treatment local water bodies are not polluted.

Question 2.
Find out how the local industries in your locality treat their wastes. Are there mechanisms in place to ensure that the soil and water are not polluted by this waste?
Answer:
We have a granite industry in my local area. There mechanisms in place to ensure that the soil and water are not polluted by this waste.

• The system for treating wastewater in the stone fabrication industry.
• The wastewater has to be collected in tanks. The solids separated from the liquid component to form slurry or sludge. The water decanted off for further treatment and recycling and the sludge dewatered prior to removal and disposal.
• Slurry separation and dewatering the slurry.
• The wastewater effluent is collected in tanks. Here the process of separating the solids suspended in the liquid takes place. Coagulants are added to the mix, this neutralizes negative charges on molecules, so they can merge to form small particles which then aggregate together forming larger masses when flocculants are added.
• These floes sink to the bottom of the tank and can be removed. This is easy to do when the tank is conical since the sediment collects in the cone at the bottom of the tank.
• In This way the water environment is saved from granite waste.

Activity – 13.9

Question 1.
Search the internet or library to find out what hazardous materials have to be dealt with while disposing of electronic items. How would these materials affect the environment ?
Answer:

• E-waste contains multiple known and suspected neurotoxicants, including lead and mercury.
• That may disrupt the development of the central nervous system during pregnancy infancy childhood and adolescence.
• Some harmful toxicants from e-waste may also impact the structural development and function of the lungs.
• The damage to the atmosphere is one of the biggest environmental impacts from e- waste.
• When electronic waste is thrown away in landfills their toxic materials seep into groundwater, affecting both land and sea animals. This can also affect the health of the people in the developing countries where most of the electronic waste is dumped.

Question 2.
Find out how plastics are recycled. Does the recycling process have any impact on the environment ?
Answer:
a. Plastic recycling has been described as the process of recovering scrap or waste plastics and reprocessing the material into useful products, sometimes completely different in form from their original state.

b. Recycled plastics, the report says, often contain higher levels of chemicals such as toxic flame retardants, benzene and other carcinogens, environmental pollutants including brominated and chlorinated dioxins, and numerous endocrine disruptors that can cause changes to the body’s natural hormone levels.