What does homozygotic mean?
Homozygous is a genetics term describing an organism, cell, or genetic state in which both copies of a particular gene or allele are identical. One allele is inherited from each parent, so the individual carries two matching versions rather than two different ones. The term is widely used in studies of inheritance, genetic disorders, breeding, and population biology. For example, a person may be described as homozygous for a disease-associated variant, meaning that both copies carry that variant. In standard Mendelian terminology, a homozygous dominant genotype expresses a dominant trait, while a homozygous recessive genotype expresses a recessive trait. The word is also used more broadly when discussing homozygous strains and forms of organisms. Its principal opposite is heterozygous, which describes carrying two different alleles at the same genetic locus. Although primarily a technical term, homozygous is readily understood wherever genetics or hereditary traits are being discussed.
adjectiveHaving two identical alleles for a particular gene, one inherited from each parent. It also describes a genetic variant or characteristic determined by such a pair of alleles.
- Having two identical alleles for a particular gene or genetic locus.
- Characterized by or producing genetically identical alleles, as in a homozygous organism, strain, or trait.
"The test confirmed that she was homozygous for the variant associated with the condition."
"Breeding experiments showed that the recessive allele was present only in the homozygous form."
"The researchers identified a homozygous mutation associated with the rare disorder."
Two matching gene alleles, one from each parent: that is the simple genetic fact behind “homozygous.”
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does homozygotic come from?
Homozygous was formed in the language of early genetics from homo-, meaning “same,” and a combining form related to zygote. The zygote element ultimately comes from Greek zygōtos, meaning “yoked together,” referring to the fusion of reproductive cells. The word shares this inheritance with forms such as heterozygote and hemizygote.
Related word forms
How homozygotic is actually used
Chiefly used in biology and genetics. It is normally used with genes, alleles, organisms, mutations, strains, or states such as dominant and recessive, and it is contrasted with heterozygous.
Easily confused with homozygotic
A homozygous individual has two identical alleles for a gene, whereas a heterozygous individual has two different alleles.