University of Adelaide researchers discovered monotremes use a completely different sex determination system than other ...

Two X chromosomes mean girl, and an X paired with a Y means boy. For the last 300 million years, this system has worked very ...

A new study in Nature shows that when pregnant mice don’t have enough iron, their (usually male) fetuses with a Y sex ...

A human’s sex is genetically determined. One of our 23 pairs of chromosomes carries genes that determine the embryo’s sex; ...

The ‘Y’ chromosome essential for developing male features is gradually disappearing What does it mean for the future of male ...

Scientists are expressing concerns about male reproductive health due to the Y chromosome's genetic material loss, ...

Scientists, for the first time, have shown that external factors can play a role in altering the sex that a mammal is born as ...

World Boxing says Algerian boxer Imane Khelif, who won gold at Paris Olympics, won't be allowed to compete until she undergoes sex testing.