Female sex chromosomes. Computer artwork of human X chromosomes (pink). In the background are female gender symbols. The X chromosome is one of two sex chromosomes. Each chromosome is comprised of two matching chromatids that are joined together at an area called a centromere. Each chromosome contains, amongst other things, the genetic material DNA (deoxyribonucleic acid), and so carries the inherited characteristics of a human. Most human cells contain 46 chromosomes as 23 pairs, of which one pair are the sex chromosomes. A female has two X chromosomes and a male has one X and one Y chromosome.