How can the sex of an offspring be determined?

The sex of an offspring is primarily determined by the combination of sex chromosomes inherited from the parents. In humans, females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The sperm cell from the male parent can carry either an X or a Y chromosome, which, when combined with the X chromosome from the female parent, determines the sex of the offspring. If the sperm carries an X chromosome, the offspring will be female (XX); if it carries a Y chromosome, the offspring will be male (XY).