AP BIOLOGY

Detailed explanation-1: -Universal donors are those with an O negative blood type. Why? O negative blood can be used in transfusions for any blood type.

Detailed explanation-2: -Answer From Rajiv K. Pruthi, M.B.B.S. For emergency transfusions, blood group type O negative blood is the variety of blood that has the lowest risk of causing serious reactions for most people who receive it. Because of this, it’s sometimes called the universal blood donor type.

Detailed explanation-3: -Type O blood is called the universal donor because: It has neither A nor B surface antigens on the red blood cells. Antigens are proteins that are capable of evoking an allergic response in someone whose whole body does not have the antigens.

Detailed explanation-4: -What makes type O negative so special? Type O negative blood has no antigens, it will not trigger an immune response, even if the recipient has a different blood type. As you might imagine, it’s a very popular resource on hospital shelves. That’s why O negative blood is in high demand yet in short supply.

Detailed explanation-5: -O negative is the most common blood type used for transfusions when the blood type is unknown. This is why it is used most often in cases of trauma, emergency, surgery and any situation where blood type is unknown. O negative is the universal blood type.