Dictionary » A » Allele



noun, plural: alleles


One member of a pair (or any of the series) of genes occupying a specific spot on a chromosome (called locus) that controls the same trait.


For example, a pair of alleles controlling the same trait, i.e. eye color: one allele codes for blue eyes, another allele for brown eyes.

In humans, simple traits such as eye color may be caused by the interaction of only one pair of alleles. But for complex traits, such as height, they are usually caused by the interactions of series of alleles. Some alleles are dominant over other alleles, as in the case of heterozygous pairings (where paired alleles are different, in contrast to homozygous pairings where alleles are the same). In the above example, since the alleles code for different eye colors they are heterozygous.

Colloquially, the term gene is used when referring to an inherited trait that is usually accompanied by a phenotype as in ‘tall genes’ or ‘bad genes’ – but the more proper (scientific) term for this is allele.

Word origin: From German Allel, shortened from Allelomorph, from English allelomorph.
Related forms: allelic (adjective), biallelic (adjective), diallelic (adjective), monoallelic (adjective), allelism (noun), nonallelic (adjective).
Synonym: allelomorph.
See also: gene, trait, loci, DNA, chromosome.

Please contribute to this project, if you have more information about this term feel free to edit this page

Results from our forum

Re: Re:

Unless you're suggesting that some "races" have better genetics than others. Allele frequencies vary between poopulations. The question is not whether there's a difference (in genetic IQ predisposition), but how large that difference is. I think the adoption ...

See entire post
by wildfunguy
Wed Jul 30, 2014 8:50 pm
Forum: Human Biology
Topic: Brain size=IQ level theory (Blacks vs Whites & Asians)
Replies: 72
Views: 258564

Microevolution verus Macroevolution

Evolution is defined as variation in the frequencies of alleles, where an allele is a specific iteration of a given gene. Microevolution is defined as variations in the frequencies of alleles below species level, in a population of organisms. Macroevolution ...

See entire post
by hackenslash
Thu Mar 06, 2014 8:57 am
Forum: Evolution
Topic: Microevolution verus Macroevolution
Replies: 16
Views: 20661

Blood Genetics help please

The A, B and O antigens of the human blood system are sugars that can be found on the surface of red blood cells. The alleles A, B and O refer to the variant forms of the proteins (enzymes) that produce the sugar antigens. The O allele enzyme is non-functional, so that the basic sugar ...

See entire post
by girlslovebarbie
Sat Feb 01, 2014 2:58 pm
Forum: Genetics
Topic: Blood Genetics help please
Replies: 2
Views: 2082

Pedigree Analysis Question

... they will produce a child which is affected. How do I do so? 3) I am then asked to calculate the probability that either A or B have a recessive allele. 4) Finally, I need to find the probability that A&B will produce a child that has a recessive allele. Thanks very much! Any help is appreciated!

See entire post
by ApothemCyte
Sat Jan 18, 2014 8:44 pm
Forum: Genetics
Topic: Pedigree Analysis Question
Replies: 0
Views: 927

Need some help segregation - independent assortment!!!

All diploid organisms have a pair of alleles for a particular trait. These alleles are present on homologous chromosomes. Segregation means that these alleles are separated during gamete formation and there is only one allele in a gamete, not ...

See entire post
by supersapien
Fri Nov 29, 2013 2:36 am
Forum: Genetics
Topic: Need some help segregation - independent assortment!!!
Replies: 1
Views: 2353
View all matching forum results

This page was last modified 12:15, 17 June 2008. This page has been accessed 346,228 times. 
What links here | Related changes | Permanent link