In humans, the sex of a newborn is determined by the type of sperm that fertilizes the egg. Males have XY chromosomes, while females have XX chromosomes. Sperm can carry either an X or a Y chromosome, while eggs always carry an X chromosome. If an X sperm fertilizes an egg, the resulting zygote will have XX chromosomes and develop into a female. If a Y sperm fertilizes an egg, the zygote will have XY chromosomes and develop into a male.
Here’s a more detailed explanation:
Sex Chromosomes:
Humans have 23 pairs of chromosomes, including one pair of sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
Sperm and Egg:
Sperm cells can carry either an X or a Y chromosome, while egg cells always carry an X chromosome.
Fertilization:
When a sperm fertilizes an egg, the resulting zygote (the first cell of a new individual) inherits one chromosome from each parent.
Sex Determination:
If the sperm carries an X chromosome, the zygote will have XX chromosomes, and the baby will develop as a female. If the sperm carries a Y chromosome, the zygote will have XY chromosomes, and the baby will develop as a male.