Q. Consider two X-linked loci, A/a and B/b. The A locus controls hair colour, with (in males) AY= red-heads, aY = yellow hair. The B locus controls baldness, with BY = bald, bY = full head of hair. Females with genotype AB/ab are crossed to random males. If the A and B loci are far enough apart on the X chromosome to be considered unlinked, what are the expected frequencies of three phenotypes (bald, red hair, yellow hair) in the male offspring of this cross? Imagine we observe 50 percent bald, 42 percent yellow hair, and 8 percent red hair. What is a recombination fraction between the bald and red/yellow loci?