Question

Arun, Deepa, Uma and Priya were asked to select a plant material which would give blue-black colour with iodine solution. Who did not select the right material?

• A. Arun selected maize grains
• B. Deepa selected wheat grains
• C. Uma selected groundnut seeds
• D. Priya selected potato

Answer 1

The correct option is C

Uma selected groundnut seeds

Explantion for the correct option:

(C) Uma selected groundnut seeds:

• Using an iodine solution, you can test for the presence of starch. When starch is present, the iodine changes from brown to blue-black or purple.
• Groundnuts are rich in proteins and oil so it does not show a blue-black colour to the iodine solution.

Explanation for the incorrect options:

• Arun, Deepa, and Priya selected maize grains, wheat grains, and potato respectively.
• All the plant material contains starch. such that they will show blue-black colour to the iodine solution.

Hence, option (C) is correct. Uma did not select the right material.