In genetics, which term is used for a trait that masks the presence of another trait?

The term that refers to a trait that masks the presence of another trait is dominant. In genetics, dominant alleles are those that express their phenotypic effect even when only one copy is present in a heterozygous condition. For example, if a dominant allele for a particular trait is present alongside a recessive allele, the dominant allele will be expressed, effectively masking the effect of the recessive allele. This characteristic is fundamental to understanding how traits are inherited and expressed in the offspring.

In contrast, recessive alleles only manifest their trait when two copies are present (homozygous condition), and co-dominant traits result in both alleles being expressed independently and visibly in the phenotype. Incomplete dominance leads to a blending of traits rather than one trait masking the other. Therefore, the correct understanding of a dominant trait is key in the study of inheritance patterns in genetics.