Zuzu is a white cat.She is genotype Ww for the "white masking gene" that reduces the number of melanocytes (pigment-containing cells).As a result,her body makes pigment,but it cannot get into the cells where it would color the fur.Zuzu's white masking gene is _____ to the melanin pigment gene because it prevents full expression of the pigment.
A)recessive
B)pleiotropic
C)epistatic
D)dominant

Question

Quizplus · Accepted Answer

The white masking gene is epistatic to the melanin pigment gene because it masks the expression of the pigment gene. This means that regardless of whether Zuzu has one or two copies of the pigment gene, her fur will still appear white due to the action of the white masking gene. This is different from a dominant or recessive gene, where the presence or absence of a particular allele would directly determine the phenotype.

Zuzu Is a White Cat