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:
$\begin{array} { | l | r | } \hline \text { wild-type } & \text { 8 } \\\hline \text { brown } & 241 \\\hline \text { briphit-red } & 239 \\\hline \text { orarnge } & \underline{12} \\\hline & 500 \\\hline\end{array}$
-What is the genotype of the wild-type mother of these progeny?

Question

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}

-What is the genotype of the wild-type mother of these progeny?

Quizplus · Accepted Answer

The wild-type mother must be heterozygous for both pr and cn mutations to produce the observed phenotypes in the progeny, indicating she carries one wild-type allele and one mutant allele for each gene.

In Drosophila, the Autosomal Recessive Pr and Cn Mutations Cause