Javier and Alyssa are brother and sister, and both have O type blood. They know that their mother has type A blood, but do not know their father's blood type. Given this information, what could their father's blood type be?
A) could be A, B, or O
B) must be O
C) must be A
D) could be AB or O

Question

Quizplus · Accepted Answer

Javier and Alyssa have O type blood, which means they must have received an O allele from each parent. Their mother, with type A blood, could be genotype AO, providing an O allele. Therefore, their father could have blood type A (genotype AO), B (genotype BO), or O (genotype OO) to provide the second O allele.

Javier and Alyssa Are Brother and Sister, and Both Have