Final answer:
The two types of antigens found on RBCs are A and B antigens, related to the ABO blood group system. Type O RBCs lack these antigens, making type O blood a universal donor. The Rh factor, particularly the D antigen, is also critical in determining Rh positive or negative blood types.
Step-by-step explanation:
The two types of antigens that can be found on RBCs are called A and B antigens, and they are the basis for the ABO blood group system. For instance, type A blood has type A antigens on the RBCs, whereas type AB blood has both A and B antigens on the RBCs. These are not found on all RBCs; for example, type O blood cells do not have either A or B antigens. Another important antigen system is the Rh factor, named after the rhesus macaque. The most significant Rh factor is the D antigen, and its presence or absence denotes Rh positive (Rh+) or Rh negative (Rh-) blood types, respectively.
Type B blood has B antigens, and type O blood, which lacks both A and B antigens, produces antibodies against them, making type O blood the universal donor, especially type O negative. ABO and Rh blood type systems are the most important when considering blood transfusions and the immune reaction that may occur due to the presence or absence of these antigens on the red blood cells.