Question

Kamar wants to know his mother's blood type. Kamar knows that his blood type is AB and his father’s blood type is heterozygous A. What can Kamar assume about his mother’s blood type?(1 point)
Responses

Kamar’s mother must be either A or O because blood type AB is considered incomplete dominant.
Kamar’s mother must be either A or O because blood type AB is considered incomplete dominant.

Kamar’s mother must be O because the recessive allele allows for Kamar to get type A from his father
Kamar’s mother must be O because the recessive allele allows for Kamar to get type A from his father

Kamar’s mother must be either AB or B because blood types AB is considered codominant
Kamar’s mother must be either AB or B because blood types AB is considered codominant

Kamar’s mother must be AB because blood type AB is inherited from one parent

Answer 1

Correct answer: Kamar’s mother must be either AB or B because blood types AB are codominant.

Explanation: Kamar is genotype IAIB. His father is heterozygous A (IAi) so could only pass IA or i — he could not pass IB. Therefore Kamar’s IB allele must have come from his mother, so she must carry an IB allele (genotype IBIB or IBi = phenotype B, or IAIB = phenotype AB).