Fertilization is the process in which a sperm cell merges with an egg cell, culminating in the creation of a zygote.

During fertilization, a sperm cell penetrates the protective barriers surrounding the egg cell and fuses with its plasma membrane. This fusion initiates a cascade of reactions that block additional sperm cells from fertilizing the same egg. Subsequently, the genetic material from the sperm combines with that of the egg, resulting in the formation of a single cell known as a zygote.

The zygote represents the first cell of a new individual and contains all the genetic information necessary for further development. It undergoes a series of cell divisions, transforming into a structure known as a blastocyst. The blastocyst then implants itself into the uterine lining, where it continues to develop into an embryo.

Fertilization is a vital component of sexual reproduction and plays a key role in promoting genetic diversity among offspring. By combining the genetic material from both the sperm and egg, a unique individual is created, inheriting traits from both parents. Without fertilization, the formation of a zygote and the subsequent stages of development would not occur.