Once it is in, a fast reaction goes through the egg cell wall to shut off all other sperm.
Sex determination in biology is about the function of sex, not what individuals look like.
This is not the same as sexual reproduction, but it results in a similar mixture of genetic traits.
In sexual reproduction the cells used for reproduction, called gametes, are either eggs or sperms. The mechanism of cell division only works when one sperm alone enters the egg.
Sex is a type of reproduction common among living things. In humans, the sex of a person depends on what sex chromosomes that person got from his or her parents.
Sex is used by plants and animals, and also by fungi and various single-celled organisms. A woman's ovum (egg cell) contains one X chromosome.
In humans, males and females usually look different.