mechanical cell
father, firewood and flow
marathon comet

Sperm this, sperm that. If you want to sound clever when referring to a single, motile, male gamete then speak spur-mat-uhzohuhn.

A spermatozoon is made of three parts: head, midpiece, flagellum (or tail). The head contains genetic material (i.e. DNA). The midpiece contains energy making cellular factories called mitochondria. The flagellum when cross-sectioned looks like a slice of tomato and contains cable-like structures that bend.

Important information encoded on DNA is transferred to the next generation. Mitochondria produce adenosine triphosphate (ATP or Red Bull for sperm) which fuels the undulation of the flagellum. The movement of the flagellum propels the spermatozoon forward to its final destination, an egg. Two become one in mammals when the sperm head fuses with the egg and in fish when the sperm enters a hole on the egg, the micropyle.