Sex determination is the process by which an individual is identified as male or female. In humans and most animals, sex is determined by the presence or absence of specific sex chromosomes. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The presence of the Y chromosome determines maleness, while the absence of it results in femaleness. In some species, environmental factors may also play a role in sex determination. For example, in some reptiles, the temperature of the egg incubation determines the sex of the offspring.
