What term refers to having two identical alleles for a trait?

The term that refers to having two identical alleles for a trait is homozygous. In genetics, an individual is considered homozygous when both alleles at a specific locus on homologous chromosomes are the same. For example, if an individual has two alleles for a trait that are both for blue eyes, they are described as homozygous for that trait.

In contrast, heterozygous describes individuals who have two different alleles for a particular trait. The terms dominant and recessive relate to how those alleles express their traits, but they do not specifically describe the genetic makeup regarding the similarity or difference of alleles. Understanding these definitions is crucial in genetics, as they help clarify how traits are inherited and expressed within organisms.