The steps necessary for setting up the experiment, ‘To demonstrate that light is necessary for photosynthesis’ are not given here in proper sequence.
I. Keep the potted plant in sunlight for 3 to 4 hours.
II. Keep the potted plant in darkness for about 48 hours.
III. Cover a leaf of the plant with a strip of black paper.
IV. Pluck the leaf and test it for starch. The correct sequence of steps is
(1) I, III, IV, II
(2) I, IV, III, II
(3) II, IV, III, I
(4) II, III, I, IV
Correct answer: (4) II, III, I, IV
Explanation:
The following sequence should be followed for setting up the experiment “To demonstrate that light is necessary for photosynthesis” -
II. Keep the potted plant in darkness for about 48 hours. - This is done to destarch the leafs so that no starch is present in the beginning of the experiment itself.
III. Cover a leaf of the plant with a strip of black paper. - This is done to prevent the synthesis of starch in that region.
I. Keep the potted plant in sunlight for 3 to 4 hours. - This is done so that photosynthesis can occur and synthesis of starch can take place.
IV. Pluck the leaf and test it for starch. - The leaf is tested for the presence of starch.
II, III, I, IV