In genetics, heterozygous refers to an organism that has two different alleles (alternative forms of a gene) at a specific locus (position) on a pair of homologous chromosomes.

The term “heterozygous” is derived from the Greek words “hetero,” meaning different, and “zygote,” which represents a cell formed by the fusion of gametes during fertilization.

In simpler terms, heterozygosity indicates the possession of two dissimilar versions of a particular gene, one inherited from each parent.