Zoogamete

A zoogamete, also known as a motile gamete, is a gamete (sex cell) that possesses the ability to move independently using flagella or cilia. The term is most often used to describe the male gamete in organisms that exhibit anisogamy or oogamy, where the male gamete is smaller and more motile than the female gamete (oogonium or egg cell).

Zoogametes are produced by various organisms, including algae, fungi, protists, and some plants (such as ferns and mosses). Their motility is crucial for fertilization, as they must actively swim or move towards the female gamete to fuse and form a zygote. The flagella or cilia enable them to navigate through a liquid medium, often guided by chemical signals (chemotaxis) released by the female gamete.

The structure of a zoogamete typically includes a head containing the nucleus and other essential organelles, and a tail consisting of one or more flagella or cilia responsible for propulsion. The head carries the genetic material to be contributed to the offspring.

The presence and characteristics of zoogametes are important factors in the classification and evolutionary relationships of various organisms.