Joe is blood type A and Ivone is type O. Their son Tomas is type A. What could be Tomas's genotype?

Question

Quizplus · Accepted Answer

A blood type is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells.
Type A blood means that there are only A proteins present. Genotypes iAiA (AA) and iAi (AO) will be type A blood and will produce only A proteins.
Type B blood means that there are only B proteins present. Genotypes iBiB (BB) and iBi (BO) will be type B blood and will produce only B proteins.
Type AB blood means that there are both A and B proteins present. The genotype iAiB (AB) will be type AB blood and will produce both A and B proteins.
Type O blood means that there are no proteins present. The genotype ii (OO) will be type O blood and will not produce any proteins.
Each biological parent donates one of two ABO genes to their child.  The A and B genes are dominant and the O gene is recessive. As it is in our example, if an O gene is paired with an A gene, the blood type will be A. Their genotype is either AA (iAiA) or AO (iAi).

Joe Is Blood Type a and Ivone Is Type O