Homozygous

Homozygous refers to an individual having two identical alleles for a particular gene. In genetics, alleles are variations of a gene that determine specific traits, such as eye color or blood type. If both alleles are the same (like two blue eye alleles), the individual is homozygous for that trait. This can be contrasted with heterozygous, where the two alleles are different. Being homozygous can affect how traits are expressed; for example, some genetic conditions can manifest only when an individual is homozygous for a certain allele.