Question

Define autogamy.

Answer 1

It is a mode of fertilization in flowering plants and sometimes in protists also.
Autogamy is used to define the reproductive mechanism in which the two gametes that undergo fusion for fertilization, comes from a single individual. It is commonly termed as self-fertilization. This mode of fertilization is mostly observed in flowering plants and in certain protists.

Complete answer:
In case of flowering plants, this mode of fertilization is often observed as self-pollination. Let us try to understand this mechanism in detail. A flower consists of a stamen (male flower part) or pistil (female flower part), or sometimes both, and some additional accessory parts such as petals, sepals, and nectar glands.Stamen consists of anther and filament. Out of these two, the anther is responsible for producing pollen and this pollen contains the male reproductive cells, sperms.In order to produce a viable seed, the pollen needs to fertilize the eggs, present in pistils. If the stamen and pistil, engaged in the process are present on the same flower, then the mechanism is said to be autogamy.
If the sperm and egg cells involved in the mechanism are coming from a different flower on the same plant, then it is said to be geitonogamy.
The most important advantage of the self-fertilization observed in flowering plants is that plants do not have to be dependent on pollinating agents that other plants rely on for fertilization.

Note:
Autogamy is self-pollination, while Xenogamy is the term used for cross pollination methods. In xenogamy, the pollen grains from the anther of one flower get deposited on the stigma of a flower on a different plant in the same species.