cytogamy

Cytogamy, also known as cell fusion or conjugation, is a biological process involving the merging of cells. This process is a form of sexual reproduction found in some organisms, such as certain protozoans and algae.123

During cytogamy, gametes, which are reproductive cells containing half the genetic material of a complete organism, fuse together. This fusion restores the full set of chromosomes, creating a diploid zygote that can develop into a new organism. In some cases, like in ciliates, cytogamy involves the exchange of genetic material between two individuals rather than a direct fusion of entire cells, and it does not immediately increase cell numbers. This process enhances genetic variation, which is crucial for a population's survival and adaptation, especially under adverse environmental conditions.23