EYE OF SCIENCE / SCIENCE PHOTO LIBRARY EYE OF SCIENCE / SCIENCE PHOTO LIBRARY
Sperm fertilizing egg. Coloured scanning electron micrograph (SEM) of sperm (blue) attempting to penetrate a human egg (brown). Each sperm has a rounded head and a long tail with which it swims. Women usually produce one large egg (ovum) per month, whereas men release some 300 million much smaller sperm (spermatozoa) which travel through the uterus to reach the egg. A few hundred sperm survive this journey and encounter the egg in the fallopian tube. However, only one sperm succeeds in penetrating the egg's wall and fertilizing the egg by fusing with its nucleus. Magnification: x5300 when printed at 10 centimetres wide.
Model release not required. Property release not required.