Deformed sperm cell. Coloured scanning electron micrograph (SEM) of an abnormal head on a sperm cell, or spermatozoon. The head contains the genetic material. All men have a few deformed sperm in their ejaculate, but an overabundance of them can mean that the man is infertile. Also, as men age the number of abnormal sperm cells they produce increases. Magnification: x13,200 when printed 10 centimetres wide.