SAT Biology Subject Test Practice Questions

Answer: D, I and II only. A person with AB blood type can never produce an offspring with O blood type.

Key Takeaway: Blood type A and blood type B are co-dominant in humans. Blood type is determined by the alleles that are inherited from both parents. A man with blood type AB inherited an A allele from one parent and a B allele from the other. The offspring of that individual will inherit either an A or B allele from the father. Since O blood type is recessive, an offspring can only have that blood type if it does not receive an A or B allele from either parent.