Question

This problem refers to the MN and ABO loci mentioned in class. It also refers to the Rh locus, which is responsible for the positive/negative part of the blood type. The Rh+ allele is dominant to the Rh- allele at this locus. Select all couples who could be the parents of a child with phenotype MN, A+ based on the phenotypes at these three loci. If none of these couples could be the parents of this child, select "None of These".

Select one or more:

Mother Type M, A+ and Father Type N, B-

Mother Type MN, AB- and Father Type M, O-

Mother Type MN, B+ and Father Type N, O+

Mother Type MN, O+ and Father Type MN, A-

None of These

Answer 1

The MN blood group is co dominant and once in herited both are expressed. In the ABO blood group system bothe A and B alleles are codominant and can be expressed simultaneously while O/I^o is recessive and as given in the question Rh+ is dominant over Rh-. The child's phenotype is MN, A+

Thus based on these information we can say that, option 1(Mother Type M, A+ and Father Type N, B-) and option 4 (Mother Type MN, O+ and Father Type MN, A-) are the correct options.

Mother Type MN, AB- and Father Type M, O- is not the option since the child would be Rh - in this case and Mother Type MN, B+ and Father Type N, O+ will give the child a B or O blood group.