Question

tang introduced a concept of donor and acceptor together in a single cell which increased the pce to 1 %

Answer 1

There are two different kinds of markers in human blood. One is categorized by the letter, A, B, or O. A means there is one, B is the other, AB is both, and O means neither. The second kind of marker is portrayed by a + or -. + means there is a marker, - means there isn't. Now, a person cannot accept blood that has markers not present in their own blood. Therefore, an A+ acceptor can use A+, A-, O+ or O-. They cannot use B bacause they don't have the B marker.  

O- blood has no markers so anyone can accept it, but an acceptor with O- blood cannot accept any kind except O-.  

AB+ has every marker so they can accept any type of blood. However, their blood can be accepted only by others with AB+.