Which human blood group lacks both A and B antigens on the surface of its red blood cells?

💡 Solution & Explanation

Individuals with blood group O lack both A and B surface antigens on their red blood cells, which prevents immune attack when their blood is transfused into recipients of various other blood groups. Conversely, blood group AB possesses both surface antigens while lacking corresponding antibodies in the plasma. A vital practical corollary is that individuals with blood group AB are recognized as universal plasma donors, whereas O-negative individuals are universal red blood cell donors.