Question

3. How would you test the presence of starch in leave
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Answer 1

Explanation:

take the leaf

add tincture of iodine

see whether it turns blackish-blue

if it turns blackish-blue then it indicates the presence of starch

Answer 2

Answer:

1. Take two healthy green potted plants of the same kind in order to remove all the starch from the leaves.
2. Keep one in the darkroom (or in a black box) for 72 hours and the other in the sunlight.
3. Now, take one leaf from each of the plants.
4. Put few drops of iodine solution on each of the leaves.
5. The leaf kept in the sunlight will turn blue-black due to the presence of starch.
6. The leaf kept in the dark will not turn blue-black because of the absence of starch.