What describes a recessive trait?

• A. A trait that is hidden unless paired
• B. A trait that is always expressed
• C. A trait influenced by the environment
• D. A trait that changes over generations

Answer: (A)

A recessive trait is hidden in individuals that carry one recessive allele because the dominant allele masks it in a heterozygous genotype. It only appears in the phenotype when the organism has two copies of the recessive allele (homozygous recessive). This is why the best description is that the trait is hidden unless paired with another recessive allele—it expresses only when both copies are recessive. The other statements don’t fit: a trait that is always expressed describes a dominant trait; environment can influence expression of some traits but isn’t the defining feature of recessive inheritance; a trait that changes over generations refers to evolution or variation over time, not the inheritance pattern itself.