Question

Give reasons for the following statement:

Stigma is a disc-like expanded part.

Answer 1

Stigma:

1. Stigma is the uppermost part of the carpel which is a disc-shaped structure.
2. The disc-shape of the stigma is to increase the surface area.
3. Pollen grains carried by different pollinating agents like wind, water and animals reach the stigma and attach to the surface of the stigma.
4. Stigma provides enough surface area for the pollen to stick to its surface so that it can further develop the pollen tube.