A recent Trump executive order defines sex based on gamete size. But the order oversimplifies genetics, hormones and reproductive biology.

Study in mice and human cadavers hints that a brain-protective gene in the chromosome becomes more active with age.

A test on lab mice may have helped scientists in California debunk a theory that part of the make up of genetics in females ...

"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).

Why do women's brains fare better in aging than men's? A study found that the second, 'silent' X chromosome turns on in the ...

Scientists at the University of Virginia have discovered that as men age, they often lose the Y chromosome in some of their ...