You are studying two linked genes in lizards. You have two females and you know that both are the same genotype, heterozygous for both genes (A/a and B/b). You testcross each female to a male that is fully homozygous recessive for both genes (a/a and b/b) and get the following progeny with the following phenotypes: $\begin{array} { l l } \text { Female } 1 & \text { Female } 2 \\A B - 37 & A B - 5 \\a b - 33 & a b - 4 \\A b - 4 & A b - 35 \\a B - 6 & a B - 36\end{array}$ How can you explain the drastic difference between these two crosses?

Question

You are studying two linked genes in lizards. You have two females and you know that both are the same genotype, heterozygous for both genes (A/a and B/b). You testcross each female to a male that is fully homozygous recessive for both genes (a/a and b/b) and get the following progeny with the following phenotypes:

\begin{array} { l l } \text { Female } 1 & \text { Female } 2 \\A B - 37 & A B - 5 \\a b - 33 & a b - 4 \\A b - 4 & A b - 35 \\a B - 6 & a B - 36\end{array}

How can you explain the drastic difference between these two crosses?