What type of inheritance results in one allele's effect being expressed fully in both homozygous and heterozygous genotypes?

The question pertains to the fundamental concepts of inheritance patterns in genetics. The correct choice relates to dominant inheritance, where one allele can mask the effect of another allele. In this scenario, when an organism possesses at least one dominant allele, its trait is expressed fully regardless of whether the organism carries one or two copies of that allele.

In a dominant inheritance pattern, homozygous individuals (with two copies of the dominant allele) showcase the trait completely, while heterozygous individuals (with one dominant and one recessive allele) still express that trait due to the presence of the dominant allele. This is a hallmark of dominant characteristics, making them easily observable even when paired with a recessive allele.

Contrastingly, recessive inheritance requires two copies of an allele to express a trait, so the trait is not observable in heterozygous individuals. Codominant inheritance manifests when both alleles contribute equally and are both expressed, leading to traits that may showcase characteristics from both alleles simultaneously. Incomplete dominance, on the other hand, produces a blending of traits, resulting in a phenotype that is intermediate between the two alleles.

Thus, the concept of dominant inheritance is crucial to understanding how certain traits manifest in both homozygous and heter