Assume that a mutation occurs in the gene responsible for the production of hexosaminidase A, such that only about 50 percent of the enzyme activity is found in the heterozygote compared with a homozygous normal individual. If heterozygotes are
phenotypically normal, we would say that the mutant allele is recessive to its normal allele.

Question

Quizplus · Accepted Answer

In genetics, a recessive allele is one that does not produce a phenotype in the presence of a dominant allele. Since heterozygotes with 50% enzyme activity are phenotypically normal, the mutant allele is recessive.

Assume That a Mutation Occurs in the Gene Responsible for the Production