On average, human males tend to be about 5 inches ( 13 centimeters) taller than females. But why?

Sex chromosomes are the genetic elements that define a person's biological sex. Learn about the XX and XY chromosomes, the sex determination system, and other chromosome combinations.

The octopus just revealed another one of its secrets: what determines its sex. University of Oregon researchers have ...

Each human cell contains 23 pairs of chromosomes that carry DNA within their nucleus. The X and Y chromosomes, commonly referred to as the sex chromosomes, are one such pair. They determine the ...

The exception was the hypothesized sex chromosome, which was present in two copies in some individuals and in a single copy in others—exactly as one would expect from a ZZ/Z0 system of sex ...

Human biological sex is determined by the sex chromosomes X and Y. In most cases, females possess two X chromosomes, while males have one X and one Y. However, there is some evidence that the Y ...

Analysis of these sex chromosomes revealed that the ancestral X chromosome of monotremes had exchanged segments with ancestral non-sex chromosomes (autosomes), which gave rise to their complex system.

The sex chromosomes of insects are thought to be around 450 million years old but have gone through more change over that time. Chromosomes determine the sex in humans and most mammals, but Kern said ...

Other ancient sex chromosomes have been discovered in plant groups like mosses and liverworts, which were some of the first plants to evolve. And insect sex chromosomes might be 450 million years ...

University of Oregon researchers have identified a sex chromosome in the California two-spot octopus. This chromosome has likely been around for 480 million years, since before octopuses split apart ...