Which of the following blood groups is universally known as the universal donor because red blood cells of this group lack both A and B surface antigens?

💡 Solution & Explanation

Blood group O red blood cells do not possess A or B antigens on their membrane surface, preventing immune agglutination when transfused into recipients of any other major blood group, making them universal donors. Group AB individuals are universal recipients because their plasma contains neither anti-A nor anti-B antibodies. Karl Landsteiner discovered the ABO blood group system in 1900. Blood plasma transports nutrients, hormones, and waste products throughout the human body.