Sex chromosomes are chromosomes, or packages of DNA, that are found inside the nucleus of all of your cells. There are two different kinds: X and Y, which determine whether you’re biologically male ...

Sex is determined in a variety of different ways throughout the animal kingdom. In mammals, it is determined genetically, not by temperature, as it can be in reptiles. Typically, females have two X ...

Chromosomes are tightly coiled structures in each of your cells that contain DNA, the code for all life. DNA is organized in segments on chromosomes called genes. Humans typically have 46 chromosomes ...