Nutrition in Plants Class 7 Extra Questions and Answers

These AP 7th Class Science Important Questions and 1st Lesson Nutrition in Plants Class 7 Extra Questions will help students prepare well for the exams.

Class 7 Science Nutrition in Plants Extra Questions

Nutrition in Plants Class 7 Important Questions

Question 1.
What is the Importance of sunlight In photosynthesis?
Answer:

• Sunlight is the source of energy In the process of photosynthesis.
• The solar energy is captured by the leaves and stored in the plant in the form of food.
• If there Is no sunlight starch cannot be prepared in plants.

Question 2.
Why do plants need nutrients?
Answer:

• Nitrogen, potassium and phosphorus are needed in less quantity.
• Micro nutrients like Boron, Zinc, Manganese, Iron, Copper, Molybdenum and Chlorine are also needed to plant.

Question 3.
What are the materials needed to know whether leaves other than green perform
photosynthesis or not?
Answer:
Red or brown coloured leaves, dropper, test tube, iodine solution and water.

Question 4.
How can you say that humans are heterotrophs?
Answer:

• Humans get food from plants or animals which in turn eat plants.
• Thus, we can say that humans are directly or indirectly depends on plants for food.

Question 5.
What are the main modes of nutrition ? Explain.
Answer:
The main modes of nutrition are : 1. Autotrophic nutrition and 2. Heterotrophic nutrition.
1. Autotrophic nutrition : The mode of nutrition in which organisms make food by themselves is called autotrophic nutrition. Ex : Plants.
2. Heterotrophic nutrition : The mode of nutrition in which organisms depend on other organisms for food is called heterotrophic nutrition. Ex : Animals.

Question 6.
Can mushrooms be called autotropes ? Why ?
Answer:

• Mushrooms are not autotrophs, they are heterotrophs.
• Mushrooms cannot prepare their food by themselves.
• They depend for food on other organisms.

Question 7.
What is chlorophyll? What is its function?
Answer:

• The green colouring pigment in plants is called chlorophyll.
• Chlorophyll captures the energy of the sunlight.
• This energy is used to synthesis food from carbondioxide and water.

Question 8.
Can photosynthesis occur in plants that are not green in colour? Explain.
Answer:

• The non – green leaves also perform photosynthesis.
• These non – green leaves also have chlorophyll.
• The large amount of red, brown and other pigments mask the green colour.
• So, photosynthesis is takes place in these leaves also.

Question 9.
Guess, what would happen if a green plant was placed in a dark room?
Answer:

• Photosynthesis does not occur when the plant leaves are not exposed to sunlight.
• The plant did not make food.

Question 10.
How do roots and stem contribute to photosynthesis ?
Answer:

• Water absorbed by the roots are transported to the leaves through the stem.
• In the leaves, it is used for the production of food.

Question 11.
Give two examples for autotrophs and heterotrophs.
Answer:

• Examples for autotrophs are plants and blue green algae.
• Examples for heterotrophs are all animals and man.

Question 12.
What are the raw materials for photosynthesis ?
Answer:

• Water
• Sunlight
• Green coloured pigment of the leaf called chlorophyll.
• Carbondioxide are the raw materials for photosynthesis.

Question 13.
What is nutrition? What are the different modes of nutrition?
Answer:
1. Nutrition is the mode of taking food by the organism and it’s utilisation by the body.
2. Two types of nutrition modes are existing on the earth. They are

• Autotrophic nutrition
• Heterotrophic nutrition

Question 14.
What are the respiratory organs of the plants? Where are they present?
Answer:
1. Stomata are the structures that help in the exchange of respiratory gases (CO₂,O₂)in plants.
2. They are present on the lower surface of the leaves.

Question 15.
How do minerals and water from the soil reach the leaves?
Answer:

• Water and minerals are transported to leaves by the vessels.
• Vessels run like pipes throughout the root, the stem, the branches and the leaves.
• They form a continuous path or passage for the nutrients to reach the leaf.

Question 16.
Mention the different parts of a living cell?
Answer:
1. Cell is the structural and functional unit of living body. The main parts of a living cell are
2.

• Cell membrane
• Nucleus and
• Cytoplasm.

Question 17.
What is the significance of chlorophyll in plants ?
Answer:

• The leaves have a green pigment called chlorophyll.
• It helps leaves to capture the energy of the sunlight.
• This energy is used to synthesise (prepare) food from carbondioxide and water.

Question 18.
Sravya said, “Photosynthesis takes place only in leaves”-Do you agree with Sravya? Why?
Answer:
1. I don’t agree with the Sravya’s statement.
2. Why because photosynthesis also takes place in other green parts of the plant – in green stems and green branches.

Question 19.
What are the adaptations seen in desert plants?
Answer:

• Desert plants have scale-or spine like leaves to reduce loss of water by transpiration.
• These plants have green stems which carryout photosynthesis.

Question 20.
What happens in the process of photosynthesis? Write it’s equation form?
Answer:
During photosynthesis, chlorophyll containing cells of leaves in the presence of sunlight, use carbondioxide and water to prepare carbohydrates
Carbondioxide + Water Carbohydrate + Oxygen.

Question 21.
What is the indication of occurence of photosynthesis in plants ?
Answer:
1. The presence of starch in leaves indicates the occurence of photosynthesis in plants.
2. When the leaf extract is tested with iodine, it is turned to blue-black colour indicates the presence of starch.

Question 22.
Does photosynthesis take place in non-green leaves? Why?
Answer:

• The leaves other than green also have chlorophyll.
• The large amounts of red, brown and other pigments mask the green colour.
• Photosynthesis takes place in these leaves also.

Question 23.
Write a brief note on heterotrophic nutrition in plants ?
Answer:

• There are some plants which do not have chlorophyll.
• They can not prepare their own food.
• Such plants depend on the food produced by other plants.
• They use the heterotrophic mode of nutrition. Ex: Cuscuta plant (Amarbel)

Question 24.
How can you say that Cuscuta is a Parasite?
Answer:

• Sometimes, we can see a yellow wiry branched structure twining around the stem and branches of a tree. This is a plant called Cuscuta.
• It does not have chlorophyll.
• It takes ready made food from the plant on which it is climbing is called host.
• Since it depends on the host for food, Cuscuta is called the parasite.

Question 25.
Boojho is confused, if the pitcher plant is green and carries out photosynthesis, then why does it feed on insects?
Answer:

• Insectivorous plants usually grow on soil deficient in nitrogen.
• Hence, they feed on insects to meet their nitrogen deficiency.
• In insectivorous plant’s leaves are modified to trap insects. Ex : Drosera, Venusfly trap, etc….
• These plants have green stems which carryout photosynthesis.

Question 26.
What are uses of fungi in our daily life ?
Answer:

• Yeast is used in the preparation of bread, cakes and alcohol.
• Mushroomsiare taken as food for nutrients.
• Some fungi are used in the preparation of medicines (antibiotics).

Question 27.
What is symbiosis? Give one example ?
Answer:

• Some organisms live together and share both shelter and nutrients. This relationship is called symbiosis.
• Examples for symbiosis are Lichens, ‘Rhizobium in root nodules of pulses.

Question 28.
What are the different functions performed by algae and fungi in Lichens ?
Answer:

• The algae prepares and provides food to the fungi.
• The fungi provide shelter, water and minerals to the algae.

Question 29.
What does Rhizobium provide to the legume plant in return what does it get from the plants?
Answer:

• Rhizobium lives in the root nodules of legume plants and fix atmospheric nitrogen in the soil.
• In turn, the plants provide food and shelter to the bacteria.
• This association is of great significance for the farmers. They can reduce the use of nitrogenous fertiliser where leguminous plants are grown.

Question 30.
Why do farmers spreading manure of fertilisers in the fields?
Answer:

• Plants absorb minerals and nutrients from the soil.
• So, their amounts in the soil keep on declining.
• Fertilisers and manures contains nutrients such as nitrogen, potassium, phosphorus etc…
• These nutrients to be added regularly to enrich the soil.

Question 31.
Where do you find fungi? How do they get food?
Answer:

• The thread like structures, which are found over rotten food (for Eg : bread) are called fungi.
• They don’t have chlorophyll, so they obtain food from dead and decaying matter.

Nutrition in Plants Extra Questions

Question 1.
What are “food factories of plants?” Why are they so called ?
Answer:

• Leaves are called “food factories of plants”.
• Chlorophyll is more in leaves.
• So, maximum photosynthesis occurs in leaves.
• That means more food is prepared in leaves.
• Hence, leaves work as “food factories of plant”.

Question 2.
What is stomata? What is the use of it ?
Answer:

• The tiny pores present on the surface of the leaves are called stomata.
• Carbondioxide enters the leave through stomata for photosynthesis.
• Oxygen prodiced in photosynthesis goes out of leaves through stomata.

Question 3.
Why does a plant need nutrients and micro nutrients?
Answer:

• Plants produce sugar first, which is converted to starch and other compounds like fats and proteins.
• To convert sugar into starch, fats and proteins, plants need some nutrients like nitrogen, potassium and phosphorus and micronutrients like boron, iron, manganese etc.
• Plants absorb these nutrient elements form the soil through their roots.

Question 4.
How does cuscuta plant get food?
Answer:

• Plants like cuscuta take readymade food from the plant on which it is climbing.
• They develop special roots called haustoria, which penetrate into the tissues of the host plant.
• And absorb food materials from the host plant.
• This is called parasitic nutrition.

Question 5.
By observing the word equation answer the following questions.
Carbondioxide + water Carbohydrate + oxygen + water
1) What is the above reaction called?
2) What are the conditions required?
3) Where does it occur?
4) What are the gases involved and released in the above reaction ?
Answer:
1) Photosynthesis.
2) Sunlight and chlorophyll.
3) It occurs in green plants which contain chloroplast.
4) Involved gas is carbondioxide and released gas is oxygen.

Question 6.
Fill the table with suitable answers.

SI. No.	Substance/condition is required for photosynthesis	Source	Parts which are involved
1.	Water	(i)	Root
2.	(ii)	Sun	Chlorophyll
3.	Carbondioxide	m	(iii)
4.	Chlorophyll	(iv)	Leaf

Answer:
i) Soil/ground
iv) Stomata
ii) Sunlight
iii) Air
v) Green parts

Question 7.
How do you appreciate the saprotrophs as they clean the environment ?
Answer:

• Saprotrophs grow on the dead bodies, decompose them and mix them with soil.
• Thus that help us by cleaning the earth surface by removing the dead and decaying matter.
• Hence, 1 appreciate the saprotrophs.

Question 8.
Imagine life on earth in the absence of photosynthesis.
Answer:
1) In the absence of photosynthesis there would not be any food.
2) The survival of almost all living organisms directly or indirectly depend upon the food made by the plants.
3) Oxygen which is essential for the survival of organism is produced during photo-synthesis. In the absence of photosynthesis, life would be impossible on the earth.

Question 9.
Draw a neat and labelled diagram of cross-section of leaf.
Answer:

Question 10.
Draw a neat and labelled diagram of Stomata.
Answer:

Question 11.
Write a short note on ‘Lichens’.
Answer:

• In Lichens, a chlorophyll containing partner, which is an algae and a fungus live together.
• The fungus provides shelter, water and minerals to the algae, in return the algae prepares and provides food to the fungus.
• The algae and fungus live together and share both shelter and nutrients. This relationship is called Symbiosis.

Question 12.
Write a short note on Mushrooms.
Answer:

• Mushrooms grow on dead and decaying matter.
• They secrete digestive juices on the decomposing matter, convert it into a solution and then absorb the nutrientss from it.
• This type of nutrition is called saprotrophic nutrition.
• Mushroom is an edible fungus, rich in nutrients.

Question 13.
Paheli’s beautiful shoes were spoiled by fungi during the rainy season. She wants to know how fungi appear suddenly during the rainy season. Can you help her?
Answer:

• Yes. The fungal spores are generally present in the air.
• When they land on wet and warm things they germinate and grow. They spoil the things like leather shoes, pickles, clothes and other articles that are left in hot and humid weather for long time.
• Paheli kept her shoes

Extra Questions of Nutrition in Plants Class 7

Question 1.
Complete the following table. Answer the following questions.
Answer:

Organisms	Type of Nutrition	Depends on
1) Green Plants	Autotrophic	Photosynthesis
2) Cuscuta	Parasitic	Host plant
3) Mushroom	Saprophytic	Dead and decaying matter
4) Pitcher plant	Partially heterotrophic	Insects

a) Which part of the pitcher plant is modified into a pitcher?
Answer: Leaf

b) Name the edible fungi.
Answer: Musbroom

C) Name the parasitic plant.
Answer: Cuscuta

d) What are the “Universal food providers”?
Answer: Green plants.

Question 2.
Write a short note on “Rhizobium”.
Answer:

• Rhizobium is a symbiotic nitrogen fixing bacteria present in the root nodules of legume plants.
• At the same time, Rhizobium can’t make it’s own food. So, it leaves in the roots of legume crops like gram, peas, moong and beans and provides them with nitrogen.
• In return, the plants provide food and shelter to the bacteria.
• Hence, they have a symbiotic relationship. This association is of great significance for the farmers. They can reduce the use of nitrogenous fertiliser where leguminous plants are grown.
• Most of the pulses (dais) are obtained from leguminous plants.

Question 3.
Write the differences between autotrophic nutrition and heterotrophic nutrition.
Answer:

Autotrophic nutrition	Heterotrophic nutrition
1) The mode of nutrition in which organisms make food by them­selves is called autotrophic nutrition. 2) Ex : Green plants. 3) Organisms have chlorophyll. 4) Prepare their own food. 5) Perform photosynthesis. 6) These organisms are producers in food chain.	1) The mode of nutrition in which organisms depends on other organisms for food is called heterotrophic nutrition. 2) Ex : Animals, mushrooms. 3) Organisms have no chlorophyll. 4) Depends on other organisms for food. 5)  Do not perform photosynthesis. 6) These organisms are consumers in food chain.

Question 4.
What happens if leaves of a green plant are coated with green paint ?
Answer:

• When the leaves of a green plant are coated with a green paint, the stomata on the surface of the leaves become clogged.
• Carbondioxide will not enter into the leaves, which is the raw material for photosynthesis.
• Moreover, green paint does not contain any chlorophyll, which is essential to trap the solar energy required for photosynthesis.
• Therefore, photosynthesis will not occur.
• The plants cannot make food.

Question 5.
Write a short note on “insectivorous plants”.
Answer:

• There are a few plants like Nepenthes, Utricularia may be green or of some other colour. These plants may perform photosynthesis but do not get all required nutrients from the soil (especially nitrogenous compounds). So, they trap small insects to get the nitrogenous compound.
• In the above plant (Nepenthes), a pitcher like or jug like structure is modified part of leaf.
• The apex of the leaf forms a lid which can open and close the mouth of the pitcher.
• Inside the pitcher, there are hair which are directed towards downside.
• When an insect lands in the pitcher, the lid closes and the trapped insect gets entangled into the hair. The lid closes and the insect is trapped.
• The insect is digested by the digestive juices secreted in the pitcher and it’s nutrients are absorbed so, these plants are called “insectivorous plants”.

Question 6.
How can you prove that the leaves other than green also carry out photosynthesis? (OR) How do you prove that the plants with red and brown coloured leaves also perform photosynthesis? (OR) How do you prove that the non – green leaves also have chlorophyll ?
Answer:
Aim: To know whether leaves other than green perform photosynthesis or not.
What you need: Red or brown coloured leaves, dropper, test tube, iodine solution, water.
What to do : Take few Red or brown coloured leaves, add few drops of water and mash them to make a paste, collect the extract by squeezing the paste (pulp). Take 5-6 drops of this extract into a test tube. Also add two drops of iodine solution. Note your observations.
What do you see: The colour of the leaf extract turns blue black.
What do you learn : This shows the presence of starch in the leaves, confirming that red or brown coloured leaves also perform photosynthesis.
These non-green leaves also have chlorophyll. The large amount of red, brown and other pigments mask the green colour. So photosynthesis takes place in these leaves also.

Question 7.
Write different types of nutrition with examples ?
Answer:
There are different types of nutrition in plants. They are:

• Autotrophic nutrition : The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic nutrition. Ex : All green plants perform photosynthesis through which they prepare their own food.
• Some plants like cuscuta do not have chlorophyll in their leaves. So, they use the heterotrophic mode of nutrition.
• It takes readymade food from the host plant with the help of wiry branched structures from the host plant. So, cuscuta is a parasite. (Parasitic mode of nutrition)
•  Some plants grow in soils deficient with nitrogen. Hence, they feed on insects to meet their nitrogen deficiency.
• The insectivorous plant’s leaves are modified to trap insects. Ex: Drosera, Venus fly trap. These insectivorous plants, etc… are partially parasitic.
• Saprotrophic nutrition: The mode of nutrition in which organisms take in nutrients from dead and decaying matter is called saprotrophic nutrition. Ex: Mushrooms, Fungi (bread mold)
• Some organisms live together and share both shelter and nutrients. This relationship is called “Symbiosis”. Ex : Lichens, Rhizobium in roots of legume plants.

Question 8.
Write a detail account of photosynthesis in plants ?
Answer:

• The leaves have a green pigment called chlorophyll.
• It helps leaves to capture the energy of the sun light.
• This energy is used to synthesize food from carbondioxide and water since, the synthesis of food occurs in the presence of sunlight, it is called photosynthesis. It is a unique process on the earth.
• The solar energy is captured by the leaves and stored in the plant in the form of food.
• The sun is the ultimate source of energy for all living organisms.
• The process can be represented in an equation.
  Carbon dioxide + Water Carbohydrate + Oxygen

Question 9.
Compare the nutrition in mushrooms and cuscuta.
Answer:

Mushrooms	Cuscuta
1) The mode of nutrition is saprophytic.	1) The mode of nutrition is parasitic.
2) Grow on dead and decaying matter.	2) Grow on host tree.
3) Uses secretion of digestive juices to absorb food.	3) Uses special roots (haustoria) to absorb food.
4) These are useful to environment by cleaning the earth surface.	4) These are not useful to environment and it also harmful to host plant.
5) It is a fungi.	5) It is a plant.
6) It does not contain chlorophyll.	6) It also does not contain chlorophyll.
7) It is a heterotroph.	7) It is also heterotroph.

Case Based / Data – Based Questions

I. Read the following information carefully and answer the questions given below.

Fungi also grow on pickles, leather, clothes and other articles that are left in hot and humid weather for long time. During the rainy season. They spoil many things.

Question 1.
Example for fungi is ……………
A) Mushroom
B) Algae
C) Bread mould
D) A and C
Answer:
D) A and C

Question 2.
Fungi also grow on …………….
A) pickles
B) leather
C) clothes
D) A and C
Answer:
D) A and C

Question 3.
Fungi are generally propagate through
A) hyphae
B) spores
C) pseudopodia
D) Binary fission
Answer:
B) spores

Question 4.
Useful fungi is…………
A) yeast
B) mushroom
C) pencillin
D) All the above
Answer:
D) All the above

Question 5.
The favourable conditions to germinate fungi is ………………
A) Wet conditions
B) Dry conditions
C) Hot conditions
D) Dry and hot conditions
Answer:
A) Wet conditions

II. Read the following information carefully and answer the following questions.

The leaves have a green pigment called chlorophyll. It helps leaves to capture the energy of the sunlight. This energy is used to prepare food from carbondioxide and water. Since, the synthesis of food occurs in the presence of sunlight, it is called photosynthesis.

Question 1.
Photosynthesis takes place in …………
A) leaves
B) stem
C) root
D) bark
Answer:
A) leaves

Question 2.
Photosynthesis in desert plants takes place in …………
A) leaves
B) stem
C) bark
D) roots
Answer:
A) leaves

Question 3.
Which gas is released in photosynthesis …………
A) oxygen
B) nitrogen
C) ozone
D) oxygen
Answer:
D) oxygen

Question 4.
Which gas is utilised in photosynthesis …………
A) oxygen
B) carbondioxide
C) nitrogen
D) ozone
Answer:
B) carbondioxide

Question 5.
The ultimate source of energy for all living organisms is …………
A) The Sun
B) The Moon
C) Water
D) Oxygen
Answer:
A) The Sun

IlI. Read the following information carefully and answer the questions that follows.

Slimy green patches in ponds or stagnant water bodies. These are generally formed by the growth of organisms called algae. They contain chlorophyll, which gives them the green colour. Algae can also prepare their own food by photosynthesis.

Question 1.
Examples for algae …………
A) Chlamydomonas
B) Amoeba
C) Euglena
D) Paramoecium
Answer:
A) Chlamydomonas

Question 2.
Which of the following can perform photosynthesis
A) Algae
B) Green plants
C) Cuscuta
D) A and B
Answer:
D) A and B

Question 3.
The main function of chlorophyll is …………
A) To trap the solar energy
B) To fix carbondioxide
C) To open stomata
D) To release oxygen
Answer:
A) To trap the solar energy

Question 4.
The end products of photosynthesis ………… [  ]
A) CO₂
B) O₂
C) Carbohydrate
D) B and C
Answer:
D) B and C

Question 5.
The carbohydrate so formed in the photosynthesis is stored as ………… [ ]
A) Glucose
B) Sucrose
C) Cellulose
D) Starch
Answer:
D) Starch