Question

While working in Thomas Hunt Morgan's lab, Alfred Sturtevantdeveloped and used a method to order and map distances betweenlinked genes. You are going to use this method to map the followinggenes: curly wings (cy), vestigial wings (vg), vermillion eyes (v)and stubble bristles (sb). A true breeding curly, vestgial wingedfemale fly is crossed with a stubble bristle, vermillion eyed malefly and all of the progeny are wild-type. The F1 tetrahybrid isthen crossed with a fly that is homozygous recessive for all fourloci and the following data is produced:

cy sb vg v 2
cy + vg + 536
+ sb vg v 19
cy sb + v 94
+ + + + 1
+ + + v 9
+ sb vg + 49
cy + vg v 116
+ sb + v 501
cy + + v 43
+ + vg + 88
+ sb + + 109
+ + vg v 24
cy + + + 17
cy sb vg + 11
cy sb + + 26