Ques 1: Why do organisms need to take food?
Ans: Food is required by all living organisms mainly for four reasons or purposes:
1. Food helps a living organism to grow. If enough food is not given or if, the food given is not of right kind, the organism will not have proper growth.
2. Another important function of food is to provide energy which is required for any living organism for movements and other activities.
Fig: Food3. Food is also needed by living organisms for replacement and repairing of their damaged parts.
4. Food provide us the power to fight against infections and diseases.
Ques 2: Distinguish between a parasite and a saprotroph.
1. A parasite takes ready-made food from the organism on which it feeds.
1. They secrete the digestive juices on the matter they live and convert it into a solution and then absorb it.
2. They feed on a living organism.
2. They feed on dead and decaying organism.
3. The organism on which it feeds is called host.
3. They do not feed on a living organism.
4. It deprives the host of valuable nutrients.
|4. There is no host at all.|
Ques 3: How would you test the presence of starch on leaves?
Ans: The presence of starch on leaves can be tested by Iodine Test. Iodine turns starch solution blue.
Ques 4: Give a brief description of the process of synthesis of food in green plants.
Ans: Leaves have a green pigment called chlorophyll. In presence of sunlight, they use carbon dioxide and water to synthesize carbohydrate. During this process oxygen is released. The carbohydrates ultimately get converted into starch. Carbon dioxide from air is taken through stomata. Water and minerals are absorbed by roots and transported to leaves.
Ques 5: Show with the help of a sketch that the plants are the ultimate source of food.
Ques 6: Fill in the blanks:
(a) Green plants are called __________ since they synthesize their own food.
(b) The foods synthesized by the plants are stored as __________.
(c) During photosynthesis solar energy is captured by the pigment called _________.
(d) During photosynthesis plants take in ____________ and release _________.
(d) carbon dioxide, oxygen
Ques 7: Name the following:
(i) A parasitic plant with yellow, slender, tubular stem.
(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.
(iii) The pores through which leaves exchange gases.
(ii) Insectivorous plants
Ques 8: Tick the correct answer:
(a) Amarbel is an example of -
Ans: (a) Parasite
(b) The plant which taps and feeds on insects is -
(ii) China rose
(iii) Pitcher plant
Ans: (b) Pitcher Plant
Fig: Pitcher Plant
Ques 9: Match the items in column I with those in column II:
3. Pitcher Plant
Fig: Amarbel: Parasite
Ques 10: Mark “T” if the statement is true and “F” if it is false:
(i) Carbon dioxide is released during photosynthesis.
(ii) Plants which synthesize their food themselves are called saprotroph.
(iii) The product of photosynthesis is not a protein.
(iv) Solar energy is converted into chemical energy during photosynthesis.
Ques 11: Choose the correct option in the following:
Which part of the plant gets carbon dioxide from the air for photosynthesis?
(i) Root hair
(iii) Leaf veins
Ans: (ii) Stomata
Ques 12: Which is the correct option in the following:
Plants take carbon dioxide from the atmosphere mainly through their -
Ans: (iv) Leaves.Fig: Leaves