Question

This information relates to the following three questions:

ABO blood type is determined by one gene with three alleles: IA, IB, and i. - IA and IB are codominant; someone with IA/IB genotype has blood type AB. - IA and IB are dominant over i; someone with IA/i genotype has blood type A, someone with IB/i genotype has blood type B. - i is recessive; someone with i/i genotype has blood type O. Red-green colourblindness is caused by a mutation in a gene on the X chromosome, with an X-linked recessive inheritance pattern. The healthy allele is represented by XC, the mutated allele is represented by Xc. A woman has blood type A and normal colour vision. She is in relationships with two different men. The first man has blood type AB and is colourblind, the second man has blood type A and normal colour vision.

1. The woman's first child is a boy, who has blood type O and is colourblind. Who is the father of this child?

a) The first man

b) The second man

c) Can’t tell with this information

2. The woman’s second child is a girl, with blood type B and normal colour vision. Who is the father of this girl?

a) The first man

b) The second man

3. What is the mother’s genotype for these two genes?

a) IA/IA XC/XC

b) IA/IA XC/Xc

c) IA/i XC/XC

d) IA/i XC/Xc

e) IA/IA Xc/Xc

c) Can’t tell with this information

Answer 1