What does homozygote mean?
A homozygote is an organism or cell with two identical alleles for a particular gene, one inherited from each parent. The term is chiefly used in genetics, biology, and animal or plant breeding. In a homozygote, the condition associated with that gene is determined by a single allele because the other parent contributes the same version. This contrasts with a heterozygote, which carries two different alleles and may display a dominant, recessive, or intermediate trait. The word is also important in discussions of inherited disorders, gene frequencies, and the appearance of recessive characteristics across generations. Although “homozygous” is the corresponding adjective, “homozygote” specifically names the organism, cell, or genotype. The distinction is especially useful when discussing breeding, self-fertilization, model organisms, and the probability that offspring will inherit identical alleles.
nounAn organism or cell that has two identical alleles for a particular gene, one inherited from each parent. The term may also refer to the genotype itself in which a gene is represented by identical alleles.
- An organism or cell possessing two identical alleles at a particular gene locus.
"Because the plant is a homozygote, its offspring will inherit the same allele from each parent."
"The laboratory identified the rare individual as a homozygote for the recessive allele."
"Self-fertilization increases the likelihood that a plant will be a homozygote for a given trait."
The regular plural is formed by adding -s.
"The study compared homozygotes and heterozygotes across several populations."
A homozygote carries the same version of a gene from each parent, making it a genetic match with itself at that locus.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does homozygote come from?
The word combines the combining form homo-, meaning “same,” with -zygote, ultimately related to Greek zygon, meaning “yoke” or “pair.” The terminology developed in genetics to describe the pairing of alleles at a gene locus. The contrastive term heterozygote uses hetero-, meaning “different,” and refers to the pairing of two unlike alleles.
Related word forms
How homozygote is actually used
This is a technical term used primarily in genetics, biology, breeding, and related fields. It is not normally used for an entire organism in casual speech, where describing the genetic condition is more usual.
Easily confused with homozygote
A homozygote has two identical alleles for a gene, whereas a heterozygote has two different alleles.