Every person, male or female, has 22 matching pairs of chromosome—one inherited from each parent—but the 23rd pair is different. This unmatched pair, known as the X and Y sex chromosomes ...

In humans and many other animals, specific chromosomes determine sex. But how did researchers discover these so-called sex chromosomes? The Sex of Offspring Is Determined by Particular Chromosomes ...

Most of the time, an embryo growing in the womb fully develops into either a male or a female with all the appropriate body parts and, many scientists believe, a mindset programmed according to ...