The Probert Encyclopaedia of Nature

SPERMATOZOON

Spermatozoon (frequently shortened to 'sperm') are the male germ cells. In the lowest forms of life the spermatozoon and the female cell, or egg, are very similar, but in the higher forms the spermatozoon becomes a highly specialised active locomotor cell, and the female egg, or ovum, becomes a larger, more passive cell. The spermatozoon is provided with a head, body and tail, the head containing a nucleus of chromatin, the body the centrosome, and the tail is a cytoplasmic thread. The tail provides the cell with the power required for movement.
Research Spermatozoon