Question

Unicellular algae X and Y of the same species were taken and experimentally, chloroplasts were removed from cell X. After some time, they both were kept in bright sunlight for few hours and then iodine test was performed on them. What will be the results ?

• A. Both X and V will turn blue-black.
• B. Cell X will turn blue-black.
• C. Cell Y will turn blue-black.
• D. Both X and Y will remain

Answer 1

The correct option is C Cell Y will turn blue-black.

Under the sunlight, alga photosynthesises and produces starch. Photosynthesis is performed by chloroplast.

As cell X lacked chloroplast, it will not make starch while the cell Y will make it. Iodine turns starch into blue-black colour. Cell Y made starch by photosynthesis, thus it will turn blue-black with iodine solution.

So, the correct answer is "option C".