Describe in detail the specimen of a potato with a drop of i

Describe in detail the specimen of a potato with a drop of iodine in comparison with a potatoe with just a drop of water under the microscope.

Solution

Answer:

Starch (a carbohydrate) can be identified by a positive iodine test. Few drops of iodine solution are added to a raw or boiled sample of the substance suspected of containing starch. If starch is present, the substance will turn blue-black in the area where the iodine solution touches it.

Substances with very small amounts of starch will turn faint blue or greenish instead of blue-black. Many materials of biological origin have high starch content. These materials can be identified with the iodine test.

The sample specimen with potato and a drop of iodine will turn blue black concluding for the presence of large amount of starch.

The sample specimen with potato and a drop of water will not undergo a change in colour.