In Drosophila, the Autosomal Recessive Pr and Cn Mutations Cause

Multiple Choice

In Drosophila, the autosomal recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes) .Flies who are homozygous recessive at both pr and cn have orange eyes.A female who has wild-type eyes is crossed to an orange-eyed male.Their progeny have the following distribution of eye colors:
$$\begin{array} { | l | r | } \hline \text { wild-type } & \text { 8 } \\\hline \text { brown } & 241 \\\hline \text { briphit-red } & 239 \\\hline \text { orarnge } & \underline{12} \\\hline & 500 \\\hline\end{array}$$
-The mother of these progeny resulted from a cross between two flies from true-breeding lines.What are the genotypes of these two lines?

A) pr cn⁺ / pr cn⁺ and pr⁺ cn / pr⁺ cn
B) pr⁺ cn⁺ / pr⁺ cn⁺ and pr cn / pr cn
C) pr⁺ cn⁺ / pr cn and pr cn / pr cn
D) pr⁺ cn / pr cn and pr cn⁺ / pr cn
E) More than one of these could be true.