English Reference

Word

allele

Phoneticsal·lele

US/əˈɫɛɫi/

UK/ɐlˈiːl/

Definition

n. one of two or more different forms of a gene that can exist at a specific place on a chromosome. It determines a specific trait, like eye color or blood type.

n. one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. It is responsible for a specific trait or characteristic in an organism.

Examples

“The gene for eye color has two different alleles.”

“If an individual inherits one dominant allele and one recessive allele for a trait, the dominant one will usually determine the physical appearance.”

“Geneticists study how different alleles interact within a population to understand the frequency of specific traits and the potential for evolutionary change over time.”

Examples

simple

“The gene for eye color has two different alleles.”

contextual

“If an individual inherits one dominant allele and one recessive allele for a trait, the dominant one will usually determine the physical appearance.”

complex

“Geneticists study how different alleles interact within a population to understand the frequency of specific traits and the potential for evolutionary change over time.”

Real-World Examples

“The Catalogue of Gene Symbols for Wheat lists up to 98 alleles (different versions of the GLU-B1 gene).”
Phys.org · 29 Sept 2026

Etymology

Borrowed from German Allel, shortened from Allelomorph, from English allelomorph. Ultimately from the Ancient Greek ἀλλήλων (allḗlōn) from ἄλλος (állos, “other”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

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English Reference