Question

Differentiate between Autogamy and Geitonogamy.

Answer 1

Hint: Pollination is the process in which pollen grains are transferred from stamen to the stigma in a flower. Autogamy is defined as the process in which pollen grains are transferred from stamen to the stigma of the same flower. Geitonogamy is the process in which pollen grains are transferred from stamen to the stigma of a different flower of the same plant.

Complete answer:
The following are the differences between autogamy and geitonogamy:

Characteristic features	Autogamy	Geitonogamy
Pollination is between	Same flower of the same plant.	Different flowers of the same plant.
Mode of pollination	Autogamy is a mechanism of self-pollination.	Geitonogamy is a cross-pollination process but is genetically self-pollination.
Evolutionary contribution	Off-springs are similar to parents, therefore no genetic variations.	Off-springs are similar to parents and therefore have no contribution to evolution.
Modifications in flower	Pollen grains can be shed directly onto flowers by autogamy flowers, and they can pollinate before the flower opens.	On the same stalk, there are many geitonogamy flowers.
Examples	Autogamy takes place in plants like sunflower, orchids, peas etc.	Maize is a classic example of geitonogamy.

Additional information:
 Xenogamy is also a type of pollination. The fertilization of a flower by pollen from a genetically distinct plant is referred to as Xenogamy. It is also known as cross-pollination. This type of pollination is seen in plants such as onions, olive, spinach etc.

Note:
In Autogamy, pollination can occur without the aid of external pollinating agents. The parental traits of a race can be retained indefinitely through geitonogamy. Both autogamy and geitonogamy result in offspring that are genetically identical to their parents.