Teratozoospermia is a common abnormality that affects sperm morphology, that is, the shape of the sperm cells is altered (for example, sperm cells with 2 heads). Defects can be found either in the head, neck, tail, or in several parts simultaneously.
Sperm development, like the development of other specialized cells, is a complex process that starts with immature sperm cells in the testes and ends with fully mature and motile sperm capable of fertilization.
— NBC News, "Scientists use test-tube science to save nearly extinct rhino," 4 July In addition to experimenting with the hybrid and northern embryos, scientists are working to turn samples of the rhinos’ skin cells into egg and sperm cells.
A single sperm cell 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. Sperm cell definition, spermatozoon. See more. Explore What's the Difference Between i.e. and e.g.? Can You Translate These Famous Phrases From Emoji?
Some types of sperm get directional information from sensing single molecules. — Chris Lee, Ars Technica, "Big transistor senses the arrival of a single molecule," 29 Oct. For instance, women who do not currently have a partner or source of sperm typically cannot utilize embryo freezing.