What do you call pairs of genes that are identical?

• A. Homogenous
• B. Heterozygous
• C. Homozygous
• D. Polygenic

Answer: (C)

The term that refers to pairs of genes that are identical is homozygous. In genetics, when an individual has two copies of the same allele at a particular gene locus, it is described as homozygous. This applies to both dominant and recessive alleles. For example, an organism that has two identical alleles for a specific trait, such as having two copies of the allele for blue eyes, is homozygous for that trait.

In contrast, the term heterozygous refers to having two different alleles at a gene locus, which means the alleles are not identical. The term homogenous is often used in contexts to describe uniformity or sameness, but it is not a standard term used in genetics to describe alleles. Polygenic refers to traits that are influenced by multiple genes, and does not apply to the concept of identical alleles. Thus, homozygous is the precise term to describe pairs of identical genes.