DR TONY BRAIN / SCIENCE PHOTO LIBRARY DR TONY BRAIN / SCIENCE PHOTO LIBRARY
Human sperm. Coloured Scanning Electron Micrograph (SEM) of several mature human sperm (also called spermatozoa). Sperm are the motile male sex cells produced in the testis. Each sperm is about 65 micrometers long and broadly divided into head (red), neck and tail (blue) regions. A pear- shaped head contains the nucleus and genetic material of the male needed to fertilize the female egg (ovum). The head is joined to the tail by a short neck. The sperm's tail enables it to swim by whiplash movements, an action that propels it to reach the ovum. Magnification: unknown.
Model release not required. Property release not required.