The following three mutations are recessive in Drosophila fruit flies: javelin (jv), thread (th), and
ebony (e). A trihybrid of unknown origin is testcrossed, producing the following results: a) Which
phenotypic class or classes are the parentals? b) Which phenotypic class or classes are the
double recombinants? c) Write the correct gene order d) Write the genotype of the trihybrid,
showing which alleles are linked (use appropriate notation) AND say whether the configuration is
cis or trans. e) Calculate the map distances (in map units) that give the relative positions of each
of these three genes. Clearly indicate and bold the distances that apply to each chromosomal
region. ff Calculate the coefficient of coincidence. Show your work. 8) Calculate interference,
Show your work.
The following three mutations are recessive in Drosophila fr.pdf
1. The following three mutations are recessive in Drosophila fruit flies: javelin (jv), thread (th), and
ebony (e). A trihybrid of unknown origin is testcrossed, producing the following results: a) Which
phenotypic class or classes are the parentals? b) Which phenotypic class or classes are the
double recombinants? c) Write the correct gene order d) Write the genotype of the trihybrid,
showing which alleles are linked (use appropriate notation) AND say whether the configuration is
cis or trans. e) Calculate the map distances (in map units) that give the relative positions of each
of these three genes. Clearly indicate and bold the distances that apply to each chromosomal
region. ff Calculate the coefficient of coincidence. Show your work. 8) Calculate interference,
Show your work
