Question

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.

Answer 1

let small x be color blindness and capital P be widows peak now man has widows peak. his father was normal. so obviously mother has widows peak. so the man is heterozygous. so genotype of man is PpXY capital X becaude he has normal vision. Women's genotype is ppxx according to the given phenotype. PpXY X ppxx gametes- PX PY pX pY px so possible genotype of children- PpXx ( widow peak, normal girl) PpxY (widow peak,color blind boy) ppxx(normal,colorblind girl) ppxY (normal,colorblind boy))