Allele Definition

Alleles are a pair of genes that occupy a specific location on a particular chromosome and control the same trait.

Alleles may appear in pairs or in multiple forms of alleles, which affect a specific trait of the offspring. Locus is the location where a gene is found on a chromosome. A pair of alleles determine the same trait, for example, eye color; one allele codes for black eyes, and another allele codes for brown eyes.

All the alleles found in an organism make up the genotype. If a pair of alleles are similar, the organism’s genotype is called homozygous. If the pair of alleles are different, the organism’s genotype is called heterozygous. A dominant allele will overrule the characteristics of a submissive allele in a heterozygous genotype. But in some traits, an allele is neither dominant nor recessive. For example, the human blood group ABO.

Main Article: Difference Between Gene and Allele are explained in detail

Frequently Asked Questions on Allele Definition


Define allele.

Alleles are defined as the pairs of genes, occupying a particular spot on a chromosome.


How many alleles are in a gene?

Two – A living organism can have two of the same alleles of a gene or two different alleles.

Further Reading:

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  1. A pair of contrasting character that consists a gene heridated from one generation to other.

    Is this also a answer of alleles??