Why blood type A can receive blood from type AB?

Answer 1

A can donate to A because they are the same type.

To donate from an A to an AB requires a little more effort. Every person's blood, except for AB blood has antigens which mark blood with "additional letters" as foreign, prompting their destruction. For example, type A blood will have anti-B antigens, type B blood will have anti-A antigens, and type O blood will have both anti-As and anti-Bs. However, AB blood has neither because it has both A and B. However, if blood from an A was put directly into an AB person, the anti-B antigens would begin to attack the AB's native blood, which would cause a number of problems. Therefore, the A blood must first be cleaned of antigens before being able to be donated.

A cannot donate to O or B because those people have anti-A antigens in their bloodstream and would just keep making it (even if you found a way to remove all of their current anti-A antigens). This would lead to the body attacking the new blood as opposed to using it.

Answer 2

Blood type A cannot receive type AB red cells for transfusion.

Group A people have anti-B in their blood, this would attack the B antigen on the surface of the AB red cells.

Answer 3

Because he or she can receive all blood type for transfusion without having blood clumps.