The process of transfer of pollen grains from male anther of a flower to female stigma of same flower or another flower is called pollination. Basically there are two kinds of pollination. These are:
- Self pollination:
It is the basic form of pollination because it only involves one flower. This type of pollination occurs when pollen grains from the anther fall directly onto the stigma of the same flower. Although this type of pollination is simple and quick, it does result in a reduction in genetic diversity because the sperm and egg cells of the same flower share genetic information.
- Cross pollination:
It is a complex type of pollination that involves the transfer of pollen from the anther of one flower to the stigma of a different flower. This type of pollination results in an increase in genetic diversity because the different flowers are sharing and mixing their genetic information to create unique offspring.
Pollination involves different pollinators. It can be either by wind or an animal.
- Wind pollination:
The wind picks up pollen from one plant and blows it onto another.
- Animal pollination:
These are organisms that travel from flower to flower and transfer pollen to each flower they visit.
Some plants don’t have flowers. Plants such as mosses and ferns reproduce by spores. Cone-bearing plants, like pine or spruce trees for example, reproduce by means of pollen that is produced by a male cone and travels by wind to a female cone of the same species. The seeds then develop in the female cone.