Male chickens carry two z sex chromosomes, while female chickens carry one z sex chromosome and one w sex chromosome. located on the z chromosome is a gene for barring. barred feathers have black and white stripes. the barred trait is dominant to the unbarred trait.

chickens have a fleshy growth on top of the head called a comb. an autosomal trait called rose comb is dominant to a trait called single comb.

an unbarred male heterozygous for the rose-comb trait is crossed with a barred female with a single comb. what proportion of the resulting progeny are expected to be barred males with single combs? give your answer as a fraction or as a decimal to the nearest hundredth.