Blood groups and transfusion compatibility MCQ - Practice Questions with Answers

In the ABO and Rh system, AB+ is the universal recipient because it has A, B and Rh antigens and therefore does not make antibodies against these common donor antigens. O- is the universal donor because its red blood cells lack A, B and Rh antigens, so they are least likely to be attacked by the recipient's antibodies. O+ cannot receive from all groups because it has anti-A and anti-B antibodies. AB+ cannot donate to all because its cells carry several antigens. O+ also is not universal because Rh-negative recipients may react to Rh-positive blood.

A person whose blood contains antibody B has anti-B antibodies in the plasma. Such a person cannot safely receive red cells carrying B antigen, so blood groups B and AB are excluded. Blood group A lacks B antigen and is compatible for this antigen condition. Blood group O has neither A nor B antigen on red blood cells and is also compatible in the ABO sense. Therefore, the suitable donor groups named in the printed choices are A or O only.