In Drosophila melanogaster you are studying three phenotypes that you suspect are linked on the same chromosome. THe homozygous recessive traits for each locus are: b leads to black body; vg leads to vestigial or poorly developed wings; bw for brown eyes.
a. if b, vg, bw are unlinked what offspring ratios would you expect to see in a test cross?
b. to determine linkage, what is the cross you would set up? show genotypes and phenotypes for the flies you would cross
c. you make he cross from b. and get the following offspring combination:phenotypes number of offspringnormal (wild type) 378
black body, vestigial wings, brown eyes 370black body 104vestigial wings, brown eyes 88black body, vestigial wngs 221brown eyes 234black body, brown eyes 32vegtigial wings 41
determine the relative gene order and map distances between the three genes