A particular variant of a gene. Expression of an allele can be recessive, dominant or intermediate. An allele is denoted by a letter (e.g. “A” or “a”), sometimes supplemented by a digit (e.g. “A1”). Example: The gene for flower colour has alleles “A” and “a”.


In common language the term “gene” is often used where, more appropriate, the term “allele” should be used.
RT: allele // allelic pair
RT: locus
RT: gene