In about one out of every 800 people, two chromosomes fuse together to form an unusual bond. These are known as Robertsonian chromosomes. It's a mystery that has long stumped scientists. Now, ...

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 ...