A geneticist is studying various phenotypic traits in the toes of rats that are controlled by a mixture of both recessive and dominant alleles. He decides to cross some of his subjects with a new mutant strain that carries a dominant trait for no toes. The progeny of this cross would be an example of
A) epigenetics.
B) chromosomal inactivation.
C) epistasis.
D) imprinting.
E) autosomal polymorphism.

Question

Quizplus · Accepted Answer

Epistasis occurs when the expression of one gene is affected by the expression of one or more independently inherited genes, such as a dominant allele masking the expression of alleles at another locus, which is the case with the dominant trait for no toes affecting the phenotypic expression of toe traits.

A Geneticist Is Studying Various Phenotypic Traits in the Toes