question_answer

                                                                         

(i) Pollen-pistil interaction is an essential step in fertilisation of angiosperms. Justify.

(ii) What steps are involved in this process?

Answer:

(i) The events from the deposition of pollen on the stigma till the entry of pollen-tube into the ovule are collectively called pollen-pistil interaction. It is an essential step in fertilisation of angiosperms and determines compatibility and incompatibility of pollen and pistil. It is a dynamic process involving pollen recognition followed by inhibition or promotion of pollen.

(ii) It includes following steps

· Reognition of compatible pollen,

· Growth of a pollen-tube,

· Entry of pollen - tube into the ovule.