NCERT Solutions for Class 7 Science Chapter 1 Nutrition in Plants
NCERT solutions for class 7 science chapter 1 nutrition in plants: Solved Exercise Questions:
Q1. Why do organisms take food?
Answer:
Organisms take food to:
(i) Get the energy to carry out life processes.
(ii) Build thier bodies.
(iii) To grow.
(iv) Repair damaged parts of their bodies.
Q2. Distinguish between a parasite and a saprotroph.
Answer:
Difference between Parasites and Saprotrophs:
|
Parasites |
Saprotrophs |
|
A parasite derives its nutrients from the living organism and it deprives the host of valuable nutrients. For example, Mosquito. |
Saprotroph organisms take in nutrients from dead and decaying matter. For example, Fungi. |
Q3. How would you test the presence of starch in leaves?
Answer:
To test the presence of starch in leaves: Perform iodine test by adding iodine solution to the leaves, if there is starch present on the leaves then iodine makes a complex of dark blue color with the starch.
Hence we can test the presence of starch in the leaves.
Q4. Give a brief description of the process of synthesis of food in green 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 synthesize (prepare) food (carbohydrates) from carbon dioxide and water. Since the synthesis of food occurs in the presence of sunlight, it is called photosynthesis.
The process equation as follows:
Q5 . Show with the help of a sketch that plants are the ultimate source of food.
Answer:
Following is the Food chain diagram to show that plant is the ultimate source of food:
Q6. Fill in the blanks:
(a) Green plants are called _________________ since they synthesise their own food.
(b) The food synthesised by plants is stored as _________________.
(c) In photosynthesis solar energy is absorbed by the pigment called ___________.
(d) During photosynthesis plants take in ______________________ and release __________________ gas.
Answer:
(a) Green plants are called autotrophs since they synthesise their own food.
(b) The food synthesised by plants is stored as starch.
(c) In photosynthesis solar energy is absorbed by the pigment called chlorophyll .
(d) During photosynthesis plants take in carbon dioxide and release oxygen gas.
Q7. Name the following:
(i)A parasitic plant with yellow, slender and branched stem.
Answer:
Cuscuta (Amarbel) is a parasitic plant with yellow, slender and branched stem.
Q7. Name the following :
(ii) A plant that is partially autotrophic.
Answer:
Pitcher plant is partially autotrophic plant.
As Pitcher plant is an insectivorous plants and insectivorous plants are not complete autotrophs but are partially autotrophs.
Q7. Name the following :
(iii) The pores through which leaves exchange gases.
Answer:
Stomata pores are responsible through which leaves exchange gases.
Q8. Tick the correct answer:
Cuscuta is an example of : (i) autotroph (ii) parasite (iii) saprotroph (iv) host
Answer:
Cuscuta is an example of :
(iI) parasite
Q8. Tick the correct answer:
(b) The plant which traps and feeds on insects is: (i) Cuscuta (ii) china rose (iv) pitcher plant (iv) rose
Answer:
The plant which traps and feed on insects is:
(iv) pitcher plant
Q9. Match the items given in Column I with those in Column II:
Column I Column II
Chlorophyll Rhizobium
Nitrogen Heterotrophs
Cuscuta Pitcher plant
Animals Leaf
Insects Parasite
Answer:
Match the columns:
|
Column I |
Matched Column II |
|
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)
(ii) Plants which synthesise their food are called saprotrophs. (T/F)
iii) The product of photosynthesis is not a protein. (T/F)
(iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)
Answer:
(i) False , Oxygen is released during photosynthesis.
(ii) False , Plants which synthesise their food are called autotrophs.
(iii) True , The product of photosynthesis is not a protein.
(iv) True , Solar energy is converted into chemical energy during photosynthesis.
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 takes in carbon dioxide from air for photosynthesis.
Q12. Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
(i) roots (ii) stem (iii ) flowers (iv) leaves
Answer:
(iv) leaves takes carbon dioxide from the atmosphere.
Q13. Why do farmers grow many fruits and vegetable crops inside large green houses? What are the advantages to the farmers?
Answer:
Farmers grow fruits and vegetable crops inside large greenhouse because it protects it from high blowing wind, and rodents also greenhouse protects the plant from the climatic conditions of outside and it can have its own suitable temperature for the growth of plants.
Farmers get advantages of the following things:
(i) They have control over their climatic conditions (Temperature, humidity etc.)
(ii) Free from pests, rodents and also from birds and animals so they have increased producibility.