Allele

This page contains too many unsourced statements and needs to be improved.

Allele could use some help. Please research the article's assertions. Whatever is credible should be sourced, and what is not should be removed.

We're all Homo here
Evolution
Relevant Hominids
A Gradual Science
Plain Monkey Business
v - t - e

An allele is a variation of a gene.

Alleles in the genome

Most genes only have one allele, however some have multiple variants. For example, the gene for eye color in humans (and some other animals) has several alleles: blue, green, brown, etc. In paired chromosomes, it is possible to have two alleles present, one in each copy of the chromosome. Where both alleles are the same in the pair, the organism is referred to as homozygous with respect to that gene. Where the alleles are different, it is referred to as heterozygous.

Dominant and recessive genes

Alleles can be described as "dominant" or "recessive" and a mixture of the two can appear in allele pairs in the genome. In some cases, one allele will be dominant while the other is recessive, and the dominant gene will be the only allele expressed. Only individuals with two recessive alleles of a gene (homozygous recessive) will express the recessive form. Genes may also be co-dominant (both or all alleles expressed) or have incomplete dominance (alleles "blend" to form an intermediate type in the phenotype).

gollark: The site of their hosting provider is down too.
gollark: I don't think it's actually that.
gollark: It is probably *not* that, actually.
gollark: Hah.
gollark: Their hosting provider says```1000% Uptime Guarantee```

See also
This evolution-related article is a stub.
You can help RationalWiki by expanding it.
This article is issued from Rationalwiki. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.