Multiple alleles refer to the existence of three or more alleles for a particular gene. Typically, there are only two alleles for a gene in a diploid organism, one from each parent. However, when there is a gene existing in more than two allelic forms, this condition is referred to as multiple allelism. These genetic variations arise usually through mutation and therefore are responsible for hereditary variations. Although individual humans (and all diploid organisms) can only have two alleles for any given gene, multiple allele traits may exist at the population level, and different individuals in the population may have different pairs of these alleles.

Some key characteristics of multiple alleles include:

• Alleles: Alleles are the pairs of genes occupying a specific spot called locus on a chromosome. Typically, there are only two alleles for a gene in a diploid organism. When there is a gene existing in more than two allelic forms, this condition is referred to as multiple allelism.

• Dominance: The wild-type allele is mostly dominant over the mutant alleles. The variant or mutant allele may be dominant, recessive, or have an intermediate phenotypic effect.

• Population level: Although individual humans (and all diploid organisms) can only have two alleles for any given gene, multiple allele traits may exist at the population level, and different individuals in the population may have different pairs of these alleles.

• Variation: Multiple alleles lead to the formation of varied phenotypic traits for a character in the population.

Examples of multiple alleles include the ABO blood groups in humans and coat color in rabbits.