What does heterozygote mean?
A heterozygote is a diploid organism or cell that has two different versions of a gene, called alleles, with one version inherited from each parent. The term is central to genetics because the relationship between those alleles can affect which traits appear. For example, a person who inherits a recessive disease-causing allele from one parent and a dominant non-disease allele from the other may be a heterozygote without developing the condition. The heterozygote can nevertheless pass the recessive allele to some offspring. In this respect, the word describes a genetic state rather than a visible characteristic, and the related adjective heterozygous is used to describe the organism or the condition itself. A homozygote, by contrast, has two identical alleles at the relevant gene locus. Heterozygote is principally used in scientific and educational contexts, including genetics, medicine, agriculture, and animal breeding.
nounAn organism or cell possessing two different alleles for a particular gene locus, one inherited from each parent. The alleles may differ in a dominant or recessive allele.
- An organism or cell with two different alleles for a particular gene locus, one inherited from each parent.
"The offspring was a heterozygote, carrying one normal allele and one variant associated with the disorder."
"The researcher identified the plant as a heterozygote for the mutation."
"Because she was a heterozygote, she could pass the recessive allele to her children without having the associated condition herself."
The standard plural adds -s; heterozygotes may refer to multiple organisms or to one organism viewed as heterozygous at several loci.
"The two heterozygotes produced offspring with three distinct genotypes."
A heterozygote carries two different genetic instructions, and a recessive allele can travel through a family without its effects appearing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does heterozygote come from?
Heterozygote combines the Greek-derived prefix hetero-, meaning “other” or “different,” with zygote, a term formed from Greek zygōtos, “fertilized” or “joined,” related to zygos, “pair.” The resulting word names an organism carrying unlike members of an allele pair and developed within the vocabulary of modern genetics.
Related word forms
How heterozygote is actually used
This is a formal scientific term used primarily in genetics, biology, breeding, and related fields. The adjective heterozygous is generally used when describing a trait or genetic state rather than the organism itself.
Easily confused with heterozygote
A heterozygote is the organism or cell itself, whereas heterozygous is the adjective describing it.
A heterozygote has two different alleles at a gene locus, while a homozygote has two identical alleles.