allele

n. one of several alternative versions of a gene that is responsible for hereditary variation (Genetics)

An allele (Pronounced: ) is a viable DNA (deoxyribonucleic acid) coding that occupies a given locus (position) on a chromosome. Usually alleles are sequences that code for a gene, but sometimes the term is used to refer to a non-gene sequence. An individual's genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype. The word came from Greek αλληλος = "each other".
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Allele /al·lele/ one of two or more alternative forms of a gene at corresponding sites on homologous chromosomes, which determine alternative [more]Allele - Community and Resources

Noun
1. one of two alternate forms of a gene that can have the same locus on homologous chromosomes and are responsible for alternative traits; "some alleles are dominant over others"
(synonym) allelomorph
(hypernym) gene, cistron, factor

n. allele, one of several alternative versions of a gene that is responsible for hereditary variation (Genetics)