Definition of Multiple Alleles
Multiple alleles are the existence of a particular gene in two or more than two alleles in a population. They are present in such a population where there exists a variety of genes. The diploid organisms have the ability to express two alleles at the same time as the genetic material is composed of two copies of every gene. Haploids organisms, despite having one copy of a gene, show many alleles in a population.
If the genotype consists of different types of alleles, it is called heterozygous genotype and if the same allele is present, then it is termed as homozygous genotype. These multiple alleles are combined with each other in a number of ways and result in different phenotypes. The various alleles express different proteins which cause a varied phenotype. The variability in the functioning of the proteins is brought by the action of different alleles.