Red-green color blindness is due to an X-linked recessive allele in humans. A widow’s peak (a hairline that comes to a peak in the middle of the forehead) is due to an autosomal dominant allele. Consider the following family history: •A man with a widow’s peak and normal color vision marries a color-blind woman with a straight hairline. The man’s father had a straight hairline, as did both of the woman’s parents. Use the family history to make predictions about the couple’s children.