What is a characteristic of a recessive allele?

A recessive allele is characterized by its expression only in the presence of another identical recessive allele. This means that for a trait to be phenotypically visible, an individual must have two copies of that recessive allele. For example, if a gene for a certain trait has one allele that is dominant and another that is recessive, the dominant allele will mask the effect of the recessive allele when only one copy is present. Hence, the phenotype associated with the recessive allele will only manifest when both alleles are of the recessive type, confirming the importance of having two copies to express the trait.

In contrast, dominant alleles will express their traits even in the presence of a recessive allele; this is why recessive characteristics are not seen if there is at least one dominant allele present. Additionally, every individual has the potential to inherit alleles from their parents, so the assertion that a recessive allele can never be inherited is incorrect. Therefore, the third point is the distinguishing feature of recessive alleles in genetics.