Homozygous refers to having inherited the same versions (alleles) of a genomic marker from each biological parent. In genetics, it means inheriting the same DNA sequence for a specific gene from each biological parent. An individual who is homozygous for a genomic marker has two identical versions of that marker, while an individual who is heterozygous for a marker has two different versions of that marker. Homozygous genes can lead to homozygous traits, such as blue eyes or red hair. Homozygous organisms that have a genotype of identical alleles for a trait or phenotype at a specific locus are described as homozygous. The opposite of homozygous is heterozygous, which means having two different alleles for a particular trait located at similar loci on paired chromosomes. In summary, homozygous refers to having identical alleles for a particular trait or gene, while heterozygous refers to having different alleles for a particular trait or gene.