Assume That Investigators Crossed a Strain of Flies Carrying the Dominant

Short Answer

Assume that investigators crossed a strain of flies carrying the dominant eye mutation Lobe on the second chromosome with a strain homozygous for the second chromosome recessive mutations smooth abdomen and straw body.The F₁ Lobe females were then backcrossed with homozygous smooth abdomen,straw body males,and the following phenotypes were observed:

$\begin{array}{lr}\text { smooth abdomen, straw body } & 820 \\ \text { Lobe } & 780 \\ \text { smooth abdomen, Lobe } & 42 \\ \text { straw body } & 58 \\ \text { smooth abdomen } & 148 \\ \text { Lobe, straw body } & 152\end{array}$


a) Give the gene order and map units between these three loci.
b) What is the coefficient of coincidence?