Each human cell contains 23 pairs of chromosomes that carry DNA within their ... Female (XX) mammals inherit one X chromosome from each parent, but males (XY) receive an X from their mother ...

"You either have XX or XY chromosomes," Rep. Nancy Mace, R-S.C., wrote Feb. 20 on X. "Those are the options." Most commonly, a person is born with two X chromosomes (female) or an X and a Y (male).

People who have one of several well-documented medical conditions do not have only XX or XY chromosomes, which typically correspond with female and male sexes, respectively. Those conditions ...