Pollination Explained
Pollination is commonly mistaken with Fertilization. They actually refer to completely different things. Pollination is however required to occur, before fertilization can take place.
Pollination refers to the process whereby pollen grains are transferred from the anthers (male) of a plant to the stigma (female) of the same, or a different plant. The pollen contains the male sex cells (gametes), and thus pollination is crucial in the sexual reproduction of flowering plants.
There are two main types of pollination: wind pollination, and animal pollination. Both are somewhat self explanatory.
Wind Pollination
This is the process whereby small, light, adapted pollen is blown from the anther of one plant to the stigma of another by the wind. Plants have many adaptations for this type of pollination such as long feathered anthers, and stigma. This type of pollination allows for plants miles apart to sexually reproduce.
Animal Pollination
This type of pollination is more common. Flower adaptations such as bright leaves, nice smells, and sweet nectar attract animals such as bees to a particular plant. Sticky pollen then sticks to the respective animal such that when it moves onto another plant the pollen is taken with it. Animals such as bees and butterflies are common animal pollinators.
A pollenizer is the plant from which the pollen is coming, whereas a pollinator is the animal which transfers the pollen. Given the somewhat random nature of such a process it is possible that pollination can occur between two plants hundreds of miles apart. At the same time, a plant can be pollinated by itself. This is self-pollination.
As pollination is vital in the sexual reproduction process of plants, plants which are grown on an industrial scale are often setup such that pollinators are purposely introduced en masse to improve the efficiency of their processes.
In a natural environment should the numbers of pollinators be diminished, be it my natural causes, or human intervention, then plant numbers can be affected. Some plants have evolved to attract specific animals. Should these animals be eliminated the plant could potentially suffer a similar fate.