Question

Incompatibility is a natural barrier in the fusion of gametes. How will you explain this statement?

Answer 1

Explanation:

In gametic incompatibility, if the sperm and ova are from different species then they do not recognize each other and hence do not fuse to form the zygote. Hence, incompatibility act as a natural barrier for fusion of gametes to prevent reproduction between individuals of different species.

Answer 2

Answer:

(1) Selt incompatibility or sell-sterility is a genetie mechanism that prevents germination of pollen on stigma of same tlower. This lavours cross polination. E.g tobacco.

(2) In pollen-pistil interaction, when pollen grain is deposited on stigma, pistil has the ability to recognize and allow germination of right type of pollen.

(3) Special type of proteins on stugmatic surlace determine compatibility or incompalibility.

(4) A physiologlcal mechanism operates to ensure successful germination of compatible pollen.

(5) Compatible pollen absorbs water and nutrients from stigmatic surface that are absent in pollen and then pollen tube emerges which grows through style.