allele Definition
one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Using allele: Examples
Take a moment to familiarize yourself with how "allele" can be used in various situations through the following examples!
Example
The gene for eye color has two alleles, one for blue eyes and one for brown eyes.
Example
Sickle cell anemia is caused by a mutation in the hemoglobin gene that produces abnormal alleles.
Example
The inheritance of blood types is determined by the presence of different alleles of the ABO gene.
Phrases with allele
an allele that is expressed when present in either the homozygous or heterozygous state
Example
In humans, the allele for brown eyes is dominant over the allele for blue eyes.
Example
In order for a person to have blue eyes, they must inherit two copies of the recessive allele.
wild-type allele
the most common allele in a population
Example
The wild-type allele for the CFTR gene produces a functional protein that regulates salt and water balance in the lungs.
Origins of allele
from Greek 'allēlón', meaning 'of one another'
Summary: allele in Brief
'Allele' [əˈliːl] refers to one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. The term is used in genetics to describe the different versions of a gene that can exist in a population. Examples include the dominant allele, which is expressed when present in either the homozygous or heterozygous state, and the recessive allele, which is only expressed when present in the homozygous state.
