Science Class 7 -Chapter 1 –Nutrition in Plants- NCERT Exercise Solution (Question-Answer) is provided below. Total 13 Questions are in this NCERT Exercise, all are solved here.
Q1. Why do organism take food?
Answer- The organisms require energy for their life process. Food plays an important role for purposes such as-
- Survive
- Growth
- Food gives us resistance to fight against disease and protect us from infections
- Maintain bodily function
- We need food for replacement and repairing damaged parts of body.
- In plants , they prepare their own food and acquire nutrients from abiotic components like :- soil , air , water and sunlight
- Animals also take food to acquire nutrients and energy.
Q2. Distinguish between a parasite and saprotrophs .
Answer –
| Saprotrophs | Parasites |
| They acquire nutrients from dead and decaying matter . | They acquire nutrients from living organism. |
| They live on dead and decaying stuff. | They mostly live on or in the host. ( Note: The organism on which it feed is called host) |
| Eg. fungi (mushrooms), and bacteria | Eg. roundworm,cuscuta |
| It is Eukaryotic as well as prokaryotic organism | It is Eukaryotic organism |
| Not harmful for the living organisms and helps environment | It is Harmful for the host and may lead to death |
| Extracellular digestion | Intracellular digestion |
Q3. How would you test the presence of starch in leaves?
Answer- The presence of starch in leaves can be tested by the iodine test. We have to take two potted plants of the same kind. We will keep one pot in a darkroom and other pot in sunlight for 72 hours. After 3-4 days, we will perform the iodine test on the leaves of the plant. Put the iodine solution on the leaf. We will observe some blue-black colour on leaves of the plant which kept in sunlight that indicates the presence of starch. But, we don’t observe blue-black colour on leaves of the plant which kept in the darkroom that indicates the absence of the starch.
Q4. Give a brief description of the presence of the synthesis of food in green plants.
Answer:
Photosynthesis: Synthesis of food occurs in the presence of sunlight, it is called photosynthesis. (Photo: light; synthesis: to combine)
Material Required for Photosynthesis: CO2, Water, Minerals, chlorophyll, Sunlight.
CO2: Comes from the atmosphere through stomata
Water & minerals: Comes from the soil through Xylem.
Chlorophyll: Present in leaf ( Green Pigment) and help leaf to capture the energy of sunlight.
Sunlight: Comes from sun & it is utilized for synthesis of food.
Explanation:
In the green plant, the synthesis of food occurs by a process called Photosynthesis. Plants use a simple chemical substance like carbon dioxide, water, and minerals for the synthesis of food.
During photosynthesis, chlorophyll-containing cells of leaves, in the presence of sunlight, use carbon dioxide and water to synthesis carbohydrates.
This process can be represented by an equation-
Carbon dioxide + water ➜ carbohydrates + oxygen
in presence of sunlight and chlorophyll.
During this process, oxygen is liberated and the formed carbohydrates are stored in the form of starch.
Q5. Show with the help of sketch that plants are the ultimate source of food.
Answer-
Producer (plant) ➜ primary consumer ( herbivores)➜ secondary consumer (carnivores) ➜ tertiary consumer ➜ decomposers
To attach a diagram of food chain…wait….
Q6. Fill in the blanks:-
(a) Green plants are called ___________ since they synthesis their own food.
Answer-autotrophs
(b) The food synthesised by plants is stored as __________.
Answer- starch
(c) In photosynthesis, solar energy is absorbed by the pigment called ________________.
Answer- chlorophyll
(d) During photosynthesis, plants take in ________________ and release __________ gas.
Answer- carbon dioxide, oxygen
Q7. Name the following:
(i) A parasitic plant with yellow , slender and branched stem.
Answer- Cuscuta
(ii) A plant that is partially autotrophic.
Answer- Insectivores plant ( Pitcher plant )
(iii) The pores through which leaves exchange gases.
Answer-Stomata
Q8. Tick the correct answer –
(a) Cuscuta is an example of:
(i) autotroph
(ii) parasite
(iii) saprotroph
(iv) host
Answer– (ii) parasite
(b) The plant which traps and feeds on insect is:
(i) cuscuta
(ii) china rose
(iii) pitcher plant
(iv) rose
Answer– (iii) pitcher plant
Q9. Match the items given in column 1 with those in column 2-
| Column 1 | Column 2 |
| Chlorophyll | Rhizobium |
| Nitrogen | Heterotrophs |
| Cuscuta | Pitcher plant |
| Animals | Leaf |
| Insects | Parasite |
Answer-
| Column 1 | Column 2 |
| Chlorophyll | Leaf |
| Nitrogen | Rhizobium |
| Cuscuta | Parasite |
| Animals | Heterotrophs |
| Insects | Pitcher plant |
Q10. Mark ‘T’ if the statement is true and ‘F’ if it is false:
(i) Carbon dioxide is released during photosynthesis. (T/F)
Answer- (F)
(ii) Plants which synthesise their food are called saprotrophs .(T/F)
Answer- (F)
(iii) The products of photosynthesis is not a protein (T/F)
Answer- (T)
(iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)
Answer- (T)
Q11. Choose the correct option from the following :
Which part of the plant takes in carbon dioxide from the air for photosynthesis?
(i) Root hair
(ii) Stomata
(iii) Leaf veins
(iv) Petals
Answer– (ii) stomata
Q12. Choose the correct option from the following:
Plants takes carbon dioxide from the atmosphere mainly through their:
(i) Roots
(ii) Stems
(iii) Flowers
(iv) Leaves
Answer- (iv) leaves
Q.13 Why do farmer grow many fruits and vegetable crops inside large greenhouses? What are the advantages to the farmer ?
Answer- Farmer grows fruits and vegetable crops in large greenhouses to provide a suitable environment (temperature, humidity, etc ) for the growth of crops and protect crops from the external climatic condition.
There are some advantages to the farmer while growing fruits and vegetable crop inside greenhouses are-
- They can grow fruits and vegetables in any season because green house environment is completely artificial .Environment of greenhouse does not depend on the external environment conditions.
- Gives more income to the farmer
- It protects the crop from wind and rodents.
- It can protects the crop from diseases.
- It protect from adverse climatic condition
Science Class 7 – Chapter 1 – Nutrition in Plants- NCERT Exercise solution (Question-Answer) ended👍👍👍
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