Fertilisasi

Fertilisasi, also known as fertilization or conception, is the biological process by which a male gamete (sperm) fuses with a female gamete (egg or ovum) to form a new diploid cell called a zygote. This event marks the beginning of a new individual's life. In sexually reproducing organisms, fertilization is a crucial step in creating offspring.

The process typically occurs internally within the female reproductive tract, though external fertilization is common in many aquatic species. For fertilization to be successful, sperm must travel from the male to the vicinity of the egg. This journey involves complex physiological mechanisms, including sperm motility and the female reproductive system's environment.

Upon reaching the egg, the sperm undergoes capacitation, a series of changes that enable it to penetrate the egg's outer layers. A single sperm then successfully fuses with the egg's plasma membrane, initiating the fusion of their genetic material. The resulting zygote contains the complete set of chromosomes, half from each parent, which will direct the development of the embryo. Following fertilization, the zygote undergoes rapid cell division, a process known as cleavage, as it travels towards the uterus for implantation in mammals. The biological significance of fertilization lies in its role in genetic recombination, which contributes to the diversity of species.