Chapter 1 Nutrition in Plants Questions and Answers Class 7
Q1. Why do organisms need to take food?
Ans: Organisms need to take food for the following purposes:
1. Food provides energy for movements. ex. walking and running.
2. Food helps in the growth of organisms.
3. Food also helps in repairing damaged tissue.
Q2. Distinguish between a parasite and a saprotroph.
|(i) Parasites feed on a host.||(i) Saprotrophs eat dead and decaying organisms.|
|(ii) The organism on which a parasite life is called a host.||(ii) they do not live on a host organism.|
Q3. How would you test the presence of starch in leaves?
Ans. We can test the presence of stars in leave by performing an iodine test.
to perform the iodine test we have to do the following steps:
1. remove the chlorophyll present in the leaves by boiling it in alcohol.
2. put 1 to 2 drops of iodine solution.
3. If the leaf’s colour changes to blue, it indicates the presence of starch.
Q4. Give a brief description of the process of synthesis of food in green plants.
Ans: In plants, food is prepared by the leaves.
the process by which leaves prepare food is called photosynthesis.
During photosynthesis, chlorophyll-containing cells of leaves, in the presence of sunlight, use carbon dioxide (CO2) and water (H2O) to synthesise carbohydrates. The process can be represented in an equation:
Q5. Show with the help of a sketch that plants are 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.
Ans: (a) autotrophs
(d) carbon dioxide, oxygen
Q7. Name the following:
(i) A parasitic plant with yellow, slender and branched stem.
(ii) A plant that is partially autotrophic.
(iii) The pores through which leaves exchange gases.
Ans: (i) cuscuta
(ii) Insectivorous plant
Q8. Tick the correct answer:
(a) Cuscuta is an example of:
(i) Autotroph (ii) Parasite (iii) Saprotroph (iv) Host
Ans: (a) (ii) Parasite
(b) The plant which traps and feeds on
(a) Cuscuta (ii) China rose (iii) Pitcher plant (iv) Rose
Ans. (b) (iii) Pitcher plant
Q9. Match the items given in Column I with those in Column II:
|Column I||Column II|
|Column I||Column II|
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)
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
Ans: (ii) Stomata
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
Ans: (iv) Leaves