Question

Leaves when treated with iodine give blue-black colour. Give reason.

Answer 1

Leaf: The leaf is a green flat structure that is very essential to the plants as they prepare food.

1. The leaves perform photosynthesis which leads to the formation of food for the plants.
2. The plants prepare food in the form of starch.
3. The starch is present in the leaves and starch when reacts with iodine solution gives blue-black colour.
4. That is why the leaves when treated with iodine turned blue-black.