Definition and purpose of pollination

Summary

Pollination is the biological transfer of pollen from the anther of a plant to the stigma of a plant, which later enables fertilisation and the production of seeds. The pollen can be moved by many kinds of pollinating agents, including animals (such as insects like bees, beetles, and butterflies; birds; and bats), as well as abiotic agents like wind, water, and rain. This transfer is crucial for the reproductive success of most flowering plants because it moves the genetic material needed for fertilisation. Pollination can occur within a species and may be either self-pollination or cross-pollination. Self-pollination happens when pollen reaches the same flower or another flower on the same individual, while cross-pollination (allogamy) involves pollen moving between different plants of the same species. In angiosperms, once pollen lands on the stigma it germinates, forms a pollen tube through the style, and delivers male gametes to the ovule, where double fertilisation produces the embryo and endosperm. In gymnosperms, fertilisation occurs via pollen reaching exposed ovules on cone-like structures, with mechanisms that differ by gymnosperm group.

Key Points

• 1

  Pollination transfers pollen to the stigma, enabling fertilisation and seed production.

• 2

  Pollination can be biotic (animals) or abiotic (wind, water, rain), and can be self-pollination or cross-pollination.

• 3

  In flowering plants, pollen germinates on the stigma, grows a pollen tube, and delivers gametes for double fertilisation.