NCERT Solutions of Chapter: Nutrition in Plants. NCERT Solutions along with worksheets and notes for Class 7.
(1) Why do organisms need to take food?
Ans– All organisms need food to get energy for growth and to do work.
(2) Distinguish between a parasite and a saprotroph.
(3) How would you test the presence of starch in leaves?
Ans –Experiment to test the presence of starch
Experiment—
Step 1-
Boil a leaf in water for 2 to three minutes. Boiling leaf in water will destroy cells and allow iodine solution to enter in it.
Step 2-
Then remove leaf from boiling water and place in it test tube. Pour ethanol in test tube. Leaf should be full dip in ethanol. Keep this test tube with leaf and ethanol in the beaker with boiling water. But flame should be switch off. Alcohol is flammable, so always switch off the flame. It will decolour the leaf.
Step 3-
Now, wash leaf with cold water.
Step 4-
Keep this leaf in a dish and put some iodine solution drops on the leaf. The colour of leaf turns blue. Blue colour shows presence of starch. It shows occurrence of photosynthesis in plants.
(4) Give a brief description of the process of synthesis of food in green plant?
Ans-Water and minerals present in the soil are absorbed by the roots and transported to the leaves by the vessels. Vessels are the pipes of plants which run throughout the root, the stem, the branches and the leaves. Stomatas are the pores on the surface of leaves which take carbon dioxide from air. The green pigment present in the leaves is called chlorophyll. leaves use energy of sunlight to synthesis food from carbon dioxide and water. This process is called photosynthesis. During the photosynthesis oxygen is released by leaves. The carbohydrates get converted into starch.
(5) Show with the help of a sketch that the plants are ultimate source of food.
Ans-Plants are ultimate source of food because only plants are the living organisms that have ability to make their food. The sketch showing plants are ultimate source of food are presenting below:
Note:-Plants are the source of food for herbivores (animals such as deer, giraffe, cow etc. that feed only on herbs.)These herbivores are source of food for carnivores (animals such as lion, tiger etc. that feed on other animals) and omnivores( animals such as humans, pig etc.that eat herbs and animals). Hence plants provide food for every living being.
(6) Fill in the blanks:
(a)Green plants are called ___________ since they synthesis their own food.
(b)The food synthesized by the plants is stored as ______.
(c)In photosynthesis solar energy is captured by the pigment called _______.
(d) During photosynthesis plants take in ____________and release __________.
Ans-
(a)Green plants are called autotrophous since they synthesis their own food.
(b)The food synthesized by the plants is stored as starch.
(c)In photosynthesis solar energy is captured by the pigment called chlorophyll.
(d) During photosynthesis plants take in carbon dioxide and release oxygen.
(7) Name the following:-
(i) A parasitic plant with yellow, slender and tubular stem.
(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.
(iii) The pores through which leaves exchange gases.
Ans-
(i) A parasitic plant with yellow, slender and tubular stem. —-Cascuta(Amarbel)
(ii) A plant that has both autotrophic and heterotrophic mode of nutrition. —-Pitcher plant
(iii) The pores through which leaves exchange gases. —-Stomata
(8)Tick the correct answer:
(a)Amarbel is an example of
(i)autotroph
(ii)parasite
(iii)saprotroph
(iv)host
Ans-
Amarbel is an example of
(i)autotroph
(ii)parasite √
(iii)saprotroph
(iv)host
(b)The plant which traps and feeds on insects is-
(i)Cuscuta
(ii)china rose
(iii)pitcher plant
(iv)rose
Ans-
The plant which traps and feeds on insects is-
(i)Cuscuta
(ii)china rose
(iii)pitcher plant √
(iv)rose
(9) Match the items given in the column 1 with those in column 2
Coloumn1 Coloumn2
(a)Chlorophyll Bacteria
(b)Nitrogen Heterotrophs
(c)Amerbel Pitcher plant
(d)animals Leaf
(e)Insects Parasite
Ans-
Coloumn1 Coloumn2
(a)Chlorophyll Bacteria (b)
(b)Nitrogen Heterotrophs (d)
(c)Amerbel Pitcher plant(e)
(d)animals Leaf (a)
(e)Insects Parasite (c)
(10) Mark T if the statement is true and F if it is false-
(i)Carbon dioxide is released during photosynthesis.
(ii)Plants which synthesis their food themselves are called saprotrophs.
(iii) The product of photosynthesis is not a protein.
(iv)Solar energy is converted into chemical energy during photosynthesis.
Ans-
(i)Carbon dioxide is released during photosynthesis. F
(ii)Plants which synthesis their food themselves 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
(11) 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) Sepals
Ans-
Which part of the plant takes in carbon dioxide from the air for photosynthesis?
(i)Root hair
(ii)Stomata √
(iii) Leaf veins
(iv) Sepals
(12) 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-
Plants take carbon dioxide from the atmosphere mainly through their:
(i)roots
(ii)stem
(iii)flowers
(iv)leaves
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