For example, a gene for eye color might have two alleles: brown and blue. A person who is homozygous for brown eyes would have two copies of the brown allele, while a person who is heterozygous for brown and blue eyes would have one copy of each allele.
The genotype of an organism is the combination of alleles that it has for a particular gene. The phenotype of an organism is the observable characteristics of the organism, which are determined by its genotype and its environment.
In the case of eye color, a person who is homozygous for brown eyes will have brown eyes, while a person who is heterozygous for brown and blue eyes will have either brown or blue eyes, depending on which allele is dominant.
Allele pairs are important because they determine the traits that an organism will have. They also play a role in evolution, as they can be passed down from generation to generation.
