Study Guide 5 Question 14&15

Question 1

Blood type in humans is controlled by two genes, one which controls ‘type’ (A, B, or O) and the other which controls Rh factor (positive or negative). At the first gene, the A and B alleles exhibit complete dominance over the O allele, and the A and B alleles exhibit codominance with each other. At the
second gene, the Rh-positive allele (+) exhibits complete dominance over the Rh-negative allele (-). In the table below, fill in the phenotype (blood type) for each genotype. For example, the genotype BO+/-
has a B allele and an O allele at the first gene; an Rh-positive allele and an Rh-negative allele at the second gene, which results in the blood type B-positive

Answer 1

Question 2

Two parents believe their baby was switched at the hospital with someone else’s child. The parents have blood types A-positive and B-positive, and the baby has blood type O-negative. Do the blood types indicate this baby does not belong to these parents?

Answer 2

If both parents are heterozygous for both traits (AO+/- and BO+/-), then they could have an OO-/- baby. There is no evidence this baby was switched