The very rare Bombay blood phenotype in humans (first discovered in Bombay, India) results in blood type O because of the lack of both the A and B antigens in individuals who are of hh genotype. This genotype results in blood type O regardless of the genotype at the unlinked I locus. If two parents are both of I^A I^B Hh genotype (type AB blood), what is the probability that their first child will also have type blood B? A) 3/8 B) 2/3 C) 1/16 D) 1/4 E) 3/16

Question

Quizplus · Accepted Answer

The child must inherit at least one H allele to express the ABO blood type. The probability of inheriting at least one H allele from two Hh parents is 3/4. The child must also inherit the I^B allele from one parent and either I^B or i from the other parent to have type B blood. The probability of this is 1/2. Therefore, the probability of the child having type B blood is (3/4) * (1/2) = 3/8.

The Very Rare Bombay Blood Phenotype in Humans (First Discovered