Humanity has been hunting for sex-based differences in the brain since at least the time of the ancient Greeks, and it has ...

which are associated with certain developmental pathways — XX chromosomes with the development of female reproductive organs and XY chromosomes with male reproductive organs. But “sex ...

Female (XX) mammals inherit one X chromosome from each parent, but males (XY) receive an X from their mother and a Y sex chromosome from their father. X and Y chromosomes determine not only the ...

In evolutionary terms, fitness is defined as an organism's ability to survive and reproduce its genes into the next ...

For example, when examining differences between male and female beetles, American researcher Nettie Stevens recognized patterns of chromosomes that differed between the two sexes. In particular ...

The head of track's governing body on Tuesday announced a policy change designed to "doggedly protect the female category": ...

two X chromosomes in the nucleus of its original egg cell and it will become a female; a Y and an X chromosome and it will become a male. But exactly what happens in the womb to make a boy or a girl?

Women have a higher proportion of key immune cells between puberty and menopause, which may be linked to the sex hormone ...

Preserving the integrity of competition in the female category is a fundamental principle of the sport of athletics,” the ...

If you're male, your body uses meiosis to create sperm cells; if you're female, it uses meiosis to create egg cells. Others cells in your body contain 46 chromosomes: 23 from your father and 23 ...

"The primary sex hormones - estrogen in females and testosterone in males - are thought to play a role in these differences, as are the sex chromosomes (XX in people registered female at birth, and XY ...

Thus, when an egg containing two nondisjoined X chromosomes, each of which carried the mutant white gene, was fertilized by a sperm cell containing the Y chromosome, the product was an XXY female ...