In Drosophila,the Genes Y,f,and V Are All X-Linked Determine the Linkage Arrangement of These Three Genes and Calculate

Essay

In Drosophila,the genes y,f,and v are all X-linked.y f v females are crossed to wild-type males and the F₁ females are test-crossed.The F₂ are distributed as follows.
$$\begin{array} { | l | r | } \hline y f v & 3210 \\\hline y f + & 72 \\\hline y + v & 1024 \\\hline y + + & 678 \\\hline + f v & 690 \\\hline + f + & 1044 \\\hline + + v & 60 \\\hline + + + & \underline { 3222 } \\\hline & 10,000 \\\hline\end{array}$$
Determine the linkage arrangement of these three genes and calculate the map distances.