Scientists discover that women's second X chromosome awakens later in life, expressing genes that protect the brain from ...

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

"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).

For one, inserting at the end of the chromosome helps the transposon avoid genes for the cell's core functioning, which ...

Scientists at the University of California, San Francisco (UCSF) may have uncovered a key reason why women tend to outlive men and maintain better cognitive function as they age. Their research ...