Suppose that pattern baldness is caused by a single autosomal gene mutation that has a dominant effect in males (either one or two copies of the mutation cause pattern baldness) and recessive effect in females (two copies of the mutation cause pattern baldness). A second gene on a different autosomal chromosome affects hair color with a ressive mutation that results in light hair instead of dark hair. Mary has no pattern baldness and dark hair, Her mother had pattern baldness and dark hair and her father had no pattern baldness and light hair. Mary marries John who has no pattern baldness and light hair. If a son is born to the couple what is probability that he has pattern baldness and dark hair like his maternal grandmother?