Male sex chromosomes. Conceptual representation of the X and Y chromosomes of a human male. Here the Y chromosome (at right) has been altered in shape and size to appear much larger and more Y-shaped than it really is. Every human cell has 46 chromosomes, of which 22 pairs are identical in both males and females. However, in males the last pair is composed of an X (left) and a much smaller Y chromosome, while females have two X chromosomes. Chromosomes carry genetic information in the form of genes and the sex chromosomes carry the genes which control sexual development.