Sperm
Male gamete that fuses with egg to form a diploid zygote.
Destination Kaikōura · CC BY 4.0
Sperm is the male reproductive cell in anisogamous sexual reproduction, where it is the smaller gamete compared to the female cell.[1] Roughly half of the nuclear genetic material for a diploid offspring is provided by sperm cells, though mitochondrial DNA is usually not included.[1][2] Spermatozoa, which are motile and possess a flagellum, are produced by animals; in contrast, some red algae and fungi generate non-motile spermatia.[1]
Quick Facts
- Latin
- spermatozoon
Facts from the source article.
Key facts and history
Isogamy is generally accepted as the ancestor to sperm and eggs.[3] Because no fossil records exist of this evolution, mathematical models are emphasized to understand it.[3] In mammals, sperm cells normally come in two types, carrying either an X or Y chromosome, which determine the offspring's sex.[4] In amniotes, spermatogenesis—the formation of sperm cells—occurs within the seminiferous tubules located in the testicles.[5]
During the spermatid phase, the tail of the sperm is formed; the entire maturation process to a fully developed spermatozoan requires about 60 days.[6] According to a common hypothesis, sperm underwent rapid evolution, yet no direct evidence supports a fast evolutionary rate or that sperm evolved before other male traits.[7]
What the cited sources add
These same glycoproteins are also present on some cancer cells, bacterial cells, parasitic worms, and HIV-infected white blood cells.[8] The FDA has banned import of Danish sperm into the US due to a risk of Creutzfeldt–Jakob disease transmission.[9][10] Denmark has a well-developed system of human sperm export, with donors who are often tall, highly educated, and have altruistic motives.[11] According to the BBC News article, specific sugar molecules on the surface of sperm are recognized by the female immune system as a signal not to reject the cell.[8]
Gallery
References
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: "Spermatium definition and meaning", Collins English Dictionary; Kumar, "Botany for Degree Gymnosperm", S. Chand Publishing, 2006, p. 261 (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Lee, "Molecular basis for maternal inheritance of human mitochondrial DNA", Nature Genetics, October 2023, p. 1632–1639 (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Pitnick, "Sperm Biology: An Evolutionary Perspective", Academic Press, 2008-11-21, p. 43–44 (we also read that source) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Scheinfeld, "You and Heredity", Frederick A. Stokes Company, 1939, p. 39 (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: "Animal reproductive system - Male systems", Encyclopedia Britannica (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: "Semen and sperm quality", Netdoctor; Gould, "Assessment of human sperm function after recovery from the female reproductive tract", Biology of Reproduction, 1984, p. 888–894 (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Fitzpatrick, "Repeated evidence that the accelerated evolution of sperm is associated with their fertilization function", Proceedings of the Royal Society B: Biological Sciences, 2020-08-12 (original not read by us) en.wikipedia.org
- "Sperm clue to 'disease immunity'", BBC News, 2007-12-17. facts only, no text reused. news.bbc.co.uk
- FDA Rules Block Import of Prized Danish Sperm Posted Aug 13, 08 7:37 AM CDT in World, Science & Health. facts only, no text reused. newser.com
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Assisted Reproduction in the Nordic Countries ncbio.org; Steven Kotler, "The God of Sperm", 26 September 2007; Steven Kotler, "The God of Sperm", 26 September 2007 (original not read by us) en.wikipedia.org
- Wikipedia, "Sperm" (CC BY-SA 4.0), which cites: Assisted Reproduction in the Nordic Countries ncbio.org; Assisted Reproduction in the Nordic Countries ncbio.org; FDA Rules Block Import of Prized Danish Sperm Posted Aug 13, 08 7:37 AM CDT in World, Science & Health; FDA Rules Block Import of Prized Danish Sperm Posted Aug 13, 08 7:37 AM CDT in World, Science & Health (we also read that source) en.wikipedia.org
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Sperm (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
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