Q1. Why do organisms take food?
Ans: Food is required by all living organisms mainly for four reasons or purposes:
Q2. Distinguish between a parasite and a saprotroph.
Q3. How would you test the presence of starch in leaves?
Ans: The presence of starch on leaves can be tested by the Iodine Test. Iodine turns starch solution blue.
Q4. Give a brief description of the process of synthesis of food in green plants.
Q5. Show with the help of a sketch that the plants are the ultimate source of food.
Ans: The food chain below shows that the plant is the ultimate producer.
Q6. Fill in the blanks:
(a) Green plants are called __________ since they synthesise their own food.
(b) The foods synthesized 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.
(d) carbon dioxide, oxygen
Q7. Name the following:
(i) A parasitic plant with yellow, slender and branched stem.
Ans: Cuscuta Cuscuta
(ii) A plant that is partially autotrophic.
Ans: Insectivorous plants (Pitcher Plant)
(iii) The pores through which leaves exchange gases.
Q8. Tick the correct answer:
(a) Cuscuta is an example of:
Ans: (ii) Parasite
(b) The plant which traps and feeds on insects is:
(ii) china rose
(iii) pitcher plant
Ans: (iii) pitcher plant
Q9. Match the items in column I with those in column II:
Q10. Mark “T” if the statement is true and “F” if it is false.
(i) Carbon dioxide is released during photosynthesis.
Oxygen is released during photosynthesis.
(ii) Plants which synthesise their food are called saprotrophs.
Plants that synthesize their food themselves are called autotrophs.
(iii) The product of photosynthesis is not a protein.
(iv) 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?
(a) Root hair
(c) Leaf veins
Correct Answer is Option (b)
- Stomata are holes made from spaces between special cells.
- These holes are where plants absorb carbon dioxide from the air. Once inside the leaf, the carbon dioxide can enter plant cells.
- Inside the plant, cells are special cell parts called chloroplasts, where photosynthesis takes place.
Q12. Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
Correct Answer is Option (d)
- Atmospheric carbon dioxide enters plants mainly through the pores in the leaves called stomata during photosynthesis.
- Stomata are the small opening on the surface of the leaves.
Q13. Why do farmers grow many fruits and vegetable crops inside large greenhouses? What are the advantages to the farmers?
Ans. Fruits and vegetable crops are grown in large greenhouses because it protects crops from external climatic conditions and provides suitable temperature for the growth of crops.
Advantages to the farmers by growing fruits and vegetable crops inside large greenhouses are: