NCERT Solutions for CBSE Class 7 Science, Chapter: 1 – Nutrition in Plants is available here. NCERT has recently published the revised edition of Class 7 Science book for the session 2019-20. With this article, you can also download the revised edition of this book. Download link is given at the end of this article
NCERT Solutions for CBSE Class 7 Science: Chapter 1 – Nutrition in Plants
Question1. Why do organisms take food?
Living organism eat food to get energy, which is essential for performing growth and maintenance of their body.
Question2. Distinguish between a parasite and a saprotroph.
These are the organism that takes nutrients from the dead or decaying organic matter.
These are the organism that grows and feeds on a living organism.
Question3. How would you test the presence of starch in leaves?
Iodine solution is used to test leaves for the presence of starch.
In order to perform this test, one needs to heat the plant leaf in boiling water for 30 seconds to 1 minute and after that heat in boiling ethanol for a few minutes. Wash with water and spread onto a white tile and add a few drops of iodine solution. The parts of the leaf that contains starch will change its colour blue-black.
Question4. Give a brief description of the process of synthesis of food in green plants.
Photo means light and synthesis means to combine. Photosynthesis is the process by which plants prepare their food. In this process green pigment in plants (known as chlorophyll) helps leaves to capture the energy of the sunlight. This energy is used to synthesise (prepare) food from carbon dioxide and water.
Question5. Show with the help of a sketch that plants are the ultimate source of food.
Question6. Fill in the blanks:
(a) Green plants are called _________________ since they synthesise their own food.
Answer (a): Autotrophs
(b) The food synthesised by plants is stored as _________________.
Answer (b): Starch
(c) In photosynthesis solar energy is absorbed by the pigment called ___________.
Answer (c): Chlorophyll
(d) During photosynthesis plants take in ______________________ and release __________________ gas.
Answer (d): Carbon dioxide, Oxygen
Question7. Name the following:
(i) A parasitic plant with yellow, slender and branched stem.
Answer (i): Cuscuta
(ii) A plant that is partially autotrophic.
Answer (ii): Pitcher plant
(iii) The pores through which leaves exchange gases.
Answer (iii): Stomata
Question8. Tick the correct answer:
(a) Cuscuta is an example of:
(i) autotroph (ii) parasite (iii) saprotroph (iv) host
Answer (a): Parasite
(b) The plant which traps and feeds on insects is:
(i) Cuscuta (ii) china rose (iv) pitcher plant (iv) rose
Answer (b): Pitcher plant
Question9. Match the items given in Column I with those in Column II:
Column I Column II
Cuscuta Pitcher plant
Insects Pitcher Plant
Question10. 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)
(i) Carbon dioxide is released during photosynthesis. (F)
(ii) Plants which synthesise their food are called saprotrophs. (F)
(iii) The product of photosynthesis is not a protein. (T)
(iv) Solar energy is converted into chemical energy during photosynthesis. (T)
Question11. 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
Question12. 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
Question13. Why do farmers grow many fruits and vegetable crops inside large green houses? What are the advantages to the farmers?
Many farmers grow fruits and vegetables inside large green housed because it protects from blowing wind, rodents birds etc. The greenhouses have several advantages, it provides optimum sunlight, temperature and water to the crop and it also protects from the harsh climatic condition. Due to it, farmers get maximum output.