You are attempting to map the breakpoints of a reciprocal balanced translocation in drosophila. you have a line of flies that is homozygous for the translocation, and carries wild-type alleles for all loci. drosophila are n = 4 (2n = 8), with three autosomal pairs and the xx or xy pair. based on your prior research, you know that the reciprocal translocation does not involve the x or y chromosomes. you have strains with normal chromosomes that are homozygous for recessive markers on chromosomes ii, iii and iv as follows: the black mutation is on chromosome ii, with bb = black, and b_ = wild-type.