Question

• It is important for chicken breeders to separate male chicks from female chicks soon after birth, but sexing chickens at this age is extremely difficult. However, a Z-linked DOMINANT allele B (Z^B barred feathers) can be used to help with this problem because the barred pattern can be seen immediately after hatching (Z^b = non-barred). CIRCLE the cross would all the chicks of one sex be barred and all those of the other sex nonbarred and SHOW YOUR WORK

                       

                    Barred male X barred female  

                      

                    Barred male X non barred female

                    Non Barred male X barred female

                    Non Barred male X non barred female

                    Several of the crosses above would work

Answer 1

Answer: Non Barred Male (Z^bZ^b) X Barred Female (Z^BW)

Male/ Female	Zb	Zb
ZB	ZBZb (Barred male)	ZBZb (Barred male)
W	ZbW (Non Barred Female)	ZbW (Non Barred Female)

From this cross, all the male progeny will be barred, and all the female progeny will be non barred, which will allow distinction of the chicks easily.