Alleles are one of two or more versions of a DNA sequence at a given genomic location. An individual inherits two alleles, one from each parent, for any given genomic location where such variation exists. If the two alleles are the same, the individual is homozygous for that allele. If the alleles are different, the individual is heterozygous. Alleles can be identical or have slight differences, and they include all the variant forms of a particular gene. These variations can have important effects within the body, influencing physical traits, risks for developing certain diseases, reactions to medications, and even the development of allergies. Alleles contribute to an organisms phenotype, which is the outward appearance of the organism. Some alleles are dominant or recessive, and they can also refer to minor DNA sequence variations between alleles that do not necessarily influence the genes phenotype.
In summary, alleles are crucial in determining an organisms genetic makeup and play a significant role in shaping physical traits and influencing various aspects of an organisms health and well-being.
