People who have one of several well-documented medical conditions do not have only XX or XY chromosomes, which typically correspond with female and male sexes, respectively. Those conditions include ...

The X and Y chromosomes, commonly referred to as the sex chromosomes, are one such pair. They determine the biological sex, reproductive organs, and sexual characteristics that develop in a person.

Gene editing techniques may eventually allow trisomy to be treated at the cellular level, according to an in vitro ...

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

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 ...

In the 1930s, Muller was surprised to note that telomeres were strangely resistant to mutagenic X-rays. Why are the ... several fundamental properties of chromosome biology; specifically, she ...