Which term refers to paired genes that are identical?

The term that refers to paired genes that are identical is "homozygous." In genetics, an organism is considered homozygous for a specific trait when it carries two identical alleles for that trait, one inherited from each parent. This genetic configuration can be crucial in determining how certain traits are expressed in the organism.

For example, in a horse with a homozygous genotype for coat color, both alleles for that color will be the same, which can lead to a predictable expression of that color. This is contrasted with heterozygous organisms, which possess two different alleles for a trait and may display a variation or blend of characteristics due to the presence of different genes.

The other terms offered are related to genetics but do not specifically address the concept of identical paired genes. "Genotype" refers to the specific genetic makeup of an organism, which can include both homozygous and heterozygous pairings, while "phenotype" describes the actual physical manifestation of traits, not the genetic composition itself. Therefore, "homozygous" is the most accurate term for paired genes that are identical.