Fertilsatsioon

Fertilsatsioon, also known as fertilization, is a process that occurs in living organisms to produce offspring. In plants, it involves the fusion of male and female gametes to form a zygote, initiating the development of a new individual. In animals, fertilization typically occurs when a sperm binds to the outside of an egg cell, penetrating the egg's membrane to fertilize the contents.

The fertilization process differs in various species. In plants, it may be facilitated through pollen, which contains sperm cells, dusting onto the stigma of a receptive flower. In animals, male gametes (sperm) generally swim to the egg cell, guided by chemical signals, and bind to the egg's surface using adhesion molecules. Invasion of the egg membrane and successful transfer of the sperm nucleus to the egg cytoplasm is often necessary for fertilization to occur.

Multiple factors can affect the likelihood of fertilization, including abiotic and biotic environmental influences. Some effects of these factors include slower pollen viability in response to increased temperature or the increased presence of pollutants in the environment. Chemicals produced by the female organism may selectively encourage or repel male gametes, optimizing outcomes in reproduction.

While fertilization in itself does not ensure the completion of the reproductive process for individual plant or animal species, it represents a crucial step toward the survival of genetic lineages.