Question

List the different types of pollination depending upon the source of the pollen grain.

Answer 1

Hint:- Pollination is the process by which pollen grains which contain the male gamete get transferred from the anther of a flower to the stigma of the same or different flower to fertilize the female gamete. It is considered to be a form of sexual fertilization in the flowering plants.

Complete Answer:-
Pollination can be of varied types depending on the classification. Based on the pollination factors, it may be biotic (when the transfer of pollen grains is facilitated by pollen vectors or pollinators like insects, birds, bats, etc) or abiotic (when the transfer of pollen happens via wind, water, rain, etc.). Based on whether the pollination occurs between flowers of different plants or flowers within the same plant, it can be cross-pollination or self-pollination, respectively. This leads to a different kind of classification which would be based on the source of the grains:

In cross-pollination, the source of pollen is from another plant which leads to genetic diversity. This is called Xenogamy. In self-pollination, the pollen can get transferred from another to stigma of the same flower. This is called Autogamy. Alternatively, it can get transferred between two flowers in the same plant. This is called Geitonogamy.

Note:- All these types of pollination occur in flowering plants, also called angiosperms like hibiscus, which results in seed formation. In the case of non-flowering plants like ferns (called gymnosperms), the plants produce spores which get dispersed, often by wind, for reproduction. This is an asexual type of reproduction.