Robert and Megan are brother and sister,and both have type O blood.They know that their mother has type A blood,but they don't know their father's blood type.Using what they know about their own blood types and their mother's,they know that their father's blood type
A) could be A,B,O,or AB.
B) must be O.
C) must be A.
D) could be A,B,or O.

Question

Quizplus · Accepted Answer

Robert and Megan both have type O blood, which means they each have two O alleles. Their mother, with type A blood, must have one A allele and one O allele. Therefore, their father must have at least one O allele to pass on to them, so his blood type could be A, B, or O.

Robert and Megan Are Brother and Sister,and Both Have Type