A characteristic determined by an allele that requires the presence of two identical alleles to be expressed.
a trait controlled by an allele that does not express itself in the heterozygous condition
The variation of a specific, identifiable gene that results in observ able traits only if the dominant trait is not present. For example, wrinkled pea seeds result only in varieties where the dominant smooth-seed trait is missing.
A trait that is expressed only when two copies of the gene responsible for the trait are present.