A spermatozoan or spermatozoon consists of a round or cylindrical nucleated cell, a short neck, and a thin motile tail. Its structure is vital to its mobility and function (i.e. sexual reproduction). The compacted nucleus contains half of the genetic information. It fuses with an ovum (the female gamete) to form a zygote. In mammals, the sex is determined by the spermatozoon. If it bears Y chromosome, the resulting offspring is a male. If X chromosome, the offspring is a female.
Word origin: Greek, from sperma, spermat-, seed + New Latin -zōon, from Greek zōion, zōon, living being.
Related forms: spermatozoal, spermatozoic (adjective).