Pollination

 It is the process of transfer of pollen grains from the anther to the stigma.

Depending on the source of pollen, pollination can be divided as follows:

Autogamy − It is the transfer of pollen grains from the anther to the stigma of the same flower.

Autogamy requires the anther and the stigma to lie close.

It also requires synchrony in the pollen release and stigma receptivity.

Plants like Viola, Oxalis, etc., produce two kinds of flowersâ€"chasmogamous flowers (with exposed anther and stigma) and cleistogamous flowers (which do not open at all and only autogamy occurs).

Geitonogamy− It is the transfer of pollens from the anther of one flower to the stigma of another flower in the same plant.

Genetically, it is similar to autogamy, but it requires pollinating agents.

Xenogamy − It is the transfer of pollen grains from the anther to the stigma of a different plant.

Pollination causes genetically different types of pollens to be brought to a plant.