# allele

/əˈɫɛɫi/ (US) · /ɐlˈiːl/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/allele
Updated: 2026-05-19

## Definition

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.

For teachers: 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.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.