Science Word Wednesday: Allele

Oct 14, 2020
By Rami Major


(Noun. /uh-LEEL/)

What does it mean?

Alleles can be considered versions of a gene, and a single gene can have many alleles. Humans have two alleles for a single gene: one from the mother, and the other from the father. The relationship between the two alleles that you have will influence your phenotype, or your physical expression of that gene. 

In this example, G and g are alleles for pea color. Capital “G” is the allele for green color and lowercase “g” is the allele for yellow color. If the offspring has at least one G allele, it will be green. However, if the offspring inherits two g alleles, it will be yellow. This relationship between alleles means that G is dominant to g, because no matter what other allele for color an offspring inherits, if it has at least one G, it will be green. Created in BioRender by Rami Major.

How do I use it in a sentence? 

I have brown eyes, so I must have inherited at least one allele for brown eyes from one of my parents. 


The word allele evolved from the German word “allelomorph,” which means “alternative form of a gene.” “Allelomorph” was coined from the Greek words “allos” meaning “other” and “morphe” meaning “form.”

Related terms




Punnett square

Fields of study in which this word is commonly used



Genetic Counseling

Edited by Anna Wheless and Emma Goldberg