Sperm
Sperm, also called spermatozoa or spermatozoon, are tiny biological cells that we use to reproduce. They are the male gamete?. A sperm resembles a tadpole and is about 4.3 millionths of a meter (0.00017 inches) long. Sperm are manufactured in the testes (testicles) and, during sex, travel down to the urethra? into a woman's vagina. There they can travel even further up the cervix?, into the uterus and up the Fallopian tubes? to meet an egg. If they meet an egg they emit a substance to clear the substance surrounding an egg and one sperm will probably make it into an egg, causing conception. This is where babies come from.
Sperm carry half the genetic information?, including XX or XY chromosomes?, to the egg and the new child. If a sperm with XX chromosomes enters the egg the child will be a girl. If a sperm with XY chromosomes enters the egg the child will be a boy. (To-do: Add information about how XX or XY sperm have different weaknesses leading to an uneven sex ratio at birth.)
There are about 250 million sperm ejected in one ejaculation during sex.
Slang and euphemisms
- Little swimmers
See also
Why does it take 250 million sperm to fertilise one egg? Because not one of them will stop and ask for directions!