Question

____ blood group individuals are called universal donors.

• A. O
• B. AB
• C. A
• D. B

Answer 1

The correct option is A O

People with type O -ve blood are called universal donors because their red blood cells have no A, B or Rh antigens and can therefore be safely given to people of any blood group. As O blood group has no antigen, it will not form agglutination with antibodies of other blood groups.

$\begin{array}{cccc}\text{Blood group}& \text{Antigens on RBCs}& \text{Antibodies in Plasma}& \text{Donor's Group}\\ \text{A}& \text{A}& \text{anti-B}& \text{A,O}\\ \text{B}& \text{B}& \text{anti-A}& \text{B,O}\\ \text{AB}& \text{A,B}& \text{nil}& \text{AB, A, B, O}\\ \text{O}& \text{nil}& \text{anti-A, B}& \text{O}\end{array}$