Male chromosomes. Computer illustration of the complete set (karyotype) of human male chromosomes with spermatozoa (sperm, blue). Within nearly every human cell there are 46 chromosomes, divided into 23 pairs. One set comes from each parent, with male sperm and the female egg both containing 23 chromosomes. Here, an X and a Y-shaped chromosome are seen as the 23rd pair (bottom right). In a female karyotype, there would be two X chromosomes. Chromosomes contain DNA (deoxyribonucleic acid), which encodes and transmits living organism's hereditary characteristics. The Y chromosome is responsible for the development of male traits.