How would you test the presence of starch in leaves?

How would you test the presence of starch in leaves?

Answer:

  • Take two potted plants of the same kind.
  • Keep one in the dark (or in a black box) for 72 hours and the other in the sunlight.
  • Take one leaf from each of the plants.
  • Put few drops of iodine solution on each of the leaves.
  • The leaf kept in the sunlight will turn blue-black due to presence of starch. The leaf kept in the dark will not turn blue-black because of absence of starch.