Which Situation Most Likely Describes a Recessive Genetic Disorder

Question

Which situation most likely describes a recessive genetic disorder?
A) The mutant allele of the gene encodes a completely nonfunctional protein.
B) The mutant allele of the gene encodes a protein that has both the normal function and a new, harmful function.
C) The mutant allele of the gene encodes a protein that has a new, harmful function.
D) The mutant allele of the gene encodes a protein with the normal function but twice the normal activity.

Accepted Answer

Recessive genetic disorders typically occur when the mutant allele produces a nonfunctional protein, requiring two copies of the mutant allele (one from each parent) for the disorder to manifest. This is because one functional allele can often compensate for the loss of function in the other allele, preventing the disorder from appearing in heterozygous individuals.