The sex of an individual with XO chromosomes depends on the species.
- In humans, XO individuals are considered female. This is because the presence of a Y chromosome is what determines maleness. In XO individuals, there is no Y chromosome, so they are considered female.
- In flies, XO individuals are male. This is because the presence of a Y chromosome is not the sole factor determining sex in flies. The number of X chromosomes plays a more significant role. Flies with two X chromosomes (XX) are female, while flies with only one X chromosome (XO) are male.
The sex determination system varies across different species. In humans, the Y chromosome is the primary determinant of sex. In flies, the number of X chromosomes plays a more important role.
