Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

3. Transfer of pollen from anther to stigma.

Explanation:

The transfer of pollen grain from the anther to the stigma of a pistil is called pollination.

It is a mechanism by which non-motile male and female gametes are brought together for the fertilization.

Following are the types of pollination:

Autogamy: The transfer of pollen grain from the anther to the stigma of the same flower.

Geitonogamy: The transfer of pollen grains from the anther to the stigma of another flower of the same plant.

This transfer involved an agent of pollination, hence functionally it is cross-pollination.

Genetically, it is similar to autogamy since the pollen grains come from the same plant.

Xenogamy: The transfer of pollen grains from the anther to the stigma of another flower of different plants of the same species.

This is the only type of pollination which brings generally different types of pollen grains to stigma.