What determines the sex of a baby?
Every egg and sperm contains 23 chromosomes. Each egg has one X chromosome while every sperm has either one X chromosome or Y chromosome. The sex of a baby is determined by where the sperm that fertilises the egg carries the X or Y chromosome.
If the sperm with X chromosome fertilised the egg, it will be a girl. If the sperm with Y chromosome fertilised the egg, it will be a boy.
Ask a Question!