The sex of a species possessing similar sex chromosomes
In humans, the homogametic sex is the female. All female gametes have the same type of sex chromosome: X-chromosome.
In other animal species, such as some birds and reptiles, the homogametic sex is the male. They have two Z sex chromosomes, thus, all gametes that they produce will bear only a Z sex chromosome.
Word origin: Greek homós (one and the same)