What term describes a genotype in which the two alleles for the characteristic are the same?

A genotype in which the two alleles for a characteristic are the same is termed homozygous. This means that both alleles inherited from an individual's parents for a specific gene are identical, whether they are dominant or recessive. For example, a plant with two alleles for tallness that are both "T" is homozygous dominant (TT), while a plant with two alleles for shortness that are both "t" is homozygous recessive (tt).

In contrast, heterozygous individuals have two different alleles for a specific gene, such as one dominant and one recessive (Tt). Polygenic refers to traits that are controlled by multiple genes, whereas multigenic denotes a characteristic influenced by multiple genes. Understanding these terms helps clarify the underlying genetic principles that determine inheritance patterns.