"A black mare was crossed to a chestnut stallion and produced a bay son and a bay daughter. the two offspring were mated to each other several times, and they produced offspring of four different coat color: black, bay, chestnut, and liver. Crossing a liver grandson back to the black mare gave a black foal, and crossing the liver granddaughter back to the chestnut stallion gave a chestnut foal. Explain how coat color is being inherited in these horses. Be sure to show the genotypes for all the above crosses, according to your explanation."