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updated: June 19, 2024


Homozygous, as related to genetics, refers to having inherited the same versions (alleles) of a genomic marker from each biological parent. Thus, an individual who is homozygous for a genomic marker has two identical versions of that marker. By contrast, an individual who is heterozygous for a marker has two different versions of that marker.



Homozygous. In diploid species, there are two alleles for each trait or gene in each pair of chromosomes in the same location, or locus. One is coming from the father and the other from the mother. An allele is one of two or more alternative forms of a gene, and are found at the same place on chromosomes. Homozygous refers to having identical alleles for a particular locus.

Amalia Dutra
Amalia Dutra, Ph.D.


Cytogenetics and Microscopy Core