heterozygous dominant definition
By Regina Bailey. Definition: Heterozygous refers to having two different alleles for a single trait. Related Terms: Allele, Genes, Homozygous. Examples: The gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r).hen the alleles of a pair are heterozygous, one is dominant and the other is recessive. Using the previous example, round seed shape (R) is dominant and wrinkled seed shape (r) is recessive.