Answer to Question #317839 in Genetics for Nhlonipho Manganyi

Question

There are three alleles for the gene that determines the ABO blood grouping system in humans namely IA, IB and IO. IA and IB are co-dominant and both are dominant over IO.

Two babies were born in a hospital on the same day (these were the only babies born in the hospital on that day). One set of parents suspected that the babies were swopped in the hospital nursery and immediately ordered blood tests to determine their blood groups. Of the parents, Mr Suspicious was blood group A and Mrs Suspicious was blood group B. The baby given to them was blood group O. Mr Convinced was blood group A and Mrs Convinced blood group AB. The baby given to them was blood group

What are the possible blood group genotypes of the parents and babies? Complete the missing values in the table below using appropriate symbols – if no values are applicable for the heterozygous or homozygous genotype, type “N” in the missing cells.