Texts: In fruit flies, there are three linked characteristics. Sable body (B) is dominant to wild-type body color (b), wild-type wings (W) are dominant to scalloped wings (w), and bar eyes (E) are dominant to wild-type eyes (e). A true-breeding female fly with a sable body, wild-type wings, and wild-type eyes is crossed with a true-breeding male with wild-type body color, scalloped wings, and bar eyes. All of the F1 progeny are found to have sable bodies, wild-type wings, and bar eyes. The testcross of an F1 female with a male with wild-type body color, scalloped wings, and wild-type eyes gave the following results:
Phenotype
Sable body, wild-type wings, bar eyes 55
Sable body, wild-type wings, wild-type eyes 422
Sable body, scalloped wings, bar eyes 2
Sable body, scalloped wings, wild-type eyes 21
Wild-type body color, wild-type wings, bar eyes 24
Wild-type body color, wild-type wings, wild-type eyes 1
Wild-type body color, scalloped wings, bar eyes 419
Wild-type body color, scalloped wings, wild-type eyes 58
a) (1 pt) Draw out the crosses (i.e. indicate the genotypes of the parents).
b) (1 pt) What are the genotypes of the progeny?
c) (2 pt) Construct a genetic map showing the map order and the distances between the genes. To do this:
First: determine which progeny represent the parental phenotypes
Second: determine the recombination frequency between each pair of genes.
Third: Draw the genetic map.