Question

Give an expermient to prove the presence of starch in leaves. [5 MARKS]

Answer 1

Each point: 1 Mark

To test the presence of starch, we perform the following experiment:

1. Dip the leaf in boiling water for a minute to kill the cells.
2. Boil the leaf in methylated spirit over a water bath till it becomes pale-white due to removal of chlorophyll. The leaf becomes hard and brittle.
3. Place it again in hot water to soften it.
4. Spread the leaf in a dish and pour iodine solution on it.
5. Presence of starch will be indicated by a blue black colour.