Why are the human sex chromosomes called “X” and “Y,” while the other 22 chromosomes are identified only by numbers? The answer begins in the late 1800s, when insect gonad cells, whose large ...

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 ...

Some of these species are stranger yet: Their sex chromosomes are bizarrely outsized. The diminutive white campion plant, for instance, packs a Y chromosome that is bigger than the entire genome ...

An idea inspired by the "X element" By the 1880s, scientists had established methods for staining chromosomes so that they could be easily visualized using a simple light microscope. With this ...

In total, most human cells contain 46 chromosomes with 22 pairs of autosomes, or non-sex chromosomes, and two sex-determining chromosomes. The sex chromosomes in humans are called X and Y.