The right answer is O negative. A,B, and O blood types describe the presence or absence of the A and B proteins on the surface of the person's red blood cells, or erythrocytes. A person with type A blood has erythrocytes with the A protein, a person with type B has the B protein, an AB individual has both, and an O individual has neither. The Rh grouping is a separate piece which looks at a different protein, the D protein. A person who is Rh positive has the D protein, while an Rh negative person does not have it.
Since the A, B, and D proteins all function as antigens, which can create an immune response, this means that blood type O negative, which lacks all of those proteins, is least likely to trigger an immune response in a recipient, earning type O negative the nickname "universal donor".
As pitabasa pointed out, a person who has type AB positive, which has all three proteins, can usually accept any blood type, because they will not react to any of the antigens. Hence AB positive is the universal recipient.
A universal donor is someone who can donate blood to anyone else, with a few rare exceptions. People with the O- blood type have traditionally been considered universal bloodcell donors. Conversely, a universal recipient can safely take blood from anyone, again with a few exceptions. People with AB+ blood have been considered universal recipients.
The universal donor of blood is blood that does not contain antigens. The only blood type that does not contain antigen is O negative. The lack of antigen in O negative blood means that other blood types will not react to O negative blood. The problem is though that people who have O negative blood can only receive O negative blood.
as per me the universal donor blood group is O- and AB+ bloodgroup is the universal reciptent
UNIVERSAL DONOR BLOOD:a blood which contains no antigens and thereby cant be attacked by the antibodies(produced during blood transfusion within the body of recipient) is said to be the 'universal donor blood'.such a blood can be given to any patient without the fear of having any strong reaction within the patient's body.
e.g:the blood group of humans that can be regarded as universal donor is ''O negative'.