Question

How would you test the presence of starch in leaves?

Answer 1

The presence of starch in leaves can be tested using iodine test.

Procedure to test for the presence of starch in leaves:
1. Dip the leaf in boiling water for a few minutes. After this, immerse it in a beaker containing alcohol.
2. Carefully place the above beaker in a water-bath and heat till the alcohol begins to boil. This decolourises the leaf.
3. Now dip the leaf in a dilute solution of iodine for a few minutes.
4. Blue - black colouration shows the presence of starch.