What is Calico cat?
[[File:British shorthair with calico coat (1).jpg|thumb|right|alt=Calico cat (Felis silvestris catus)| Calico cat]] '''Calico cat''' is an American name for cats with three colors. Outside of North America they are usually called '''tortoiseshell cats''' or 'tortie-and-white'.<ref>Sayer, Angela 1996. ''Encyclopedia of the Cat''. London: Chancellor Press, p219. {{ISBN|1-85152-923-3}}</ref> A calico cat has a coat of orange or brown and black spots on a white background.<ref>Furstinger, Nancy. (2005). [https://books.google.com/books?id=p4Bc0A7EHrQC&pg=PA6 ''Calico Cats,'' p. 6].</ref> It is not a [[Cat breed|breed]] of cat.<ref>Furstinger, [https://books.google.com/books?id=p4Bc0A7EHrQC&pg=PA7 p. 7].</ref> Nearly all calico cats are female.<ref>Rice, Dan. (1997). [https://books.google.com/books?id=eYWC9vuagJ8C&pg=PA17 ''Complete book of cat breeding, '' p. 17].</ref> There are male calico cats, but they are very rare. Only one of every 3000 calico cats are male.<ref>{{cite web|url=https://www.krem.com/article/news/local/verify/verify-are-calico-cats-always-female-are-orange-cats-always-male/293-8d6a09df-16fa-4634-90b9-d66307d8ca5e|title=Verify: Are calico cats always female? Are orange cats always male?|date=15 March 2019|last=Elfalan|first=Kierra|work=KREM|accessdate=25 April 2020}}</ref> ==Genetics== A single [[X chromosome]] can have either a black [[allele]] of the coloration [[gene]] or an orange version, but not both. However, a female cat has two X chromosomes, so it can have both versions, black on one chromosome and orange on the other, making the cat a calico. A male cat usually has one X chromosome and one Y chromosome. A [[Y chromosome]] does not have a color gene, so the cat can have either an orange or a black gene, but not both. Calico cats are often used as an example in [[biology]] classes when discussing [[sex chromosome]]s. During the early stages of development, when the cat is still an [[embryo]], in each [[cell]] one of the X chromosomes (either the black one or the orange one) deactiv