Question

Blood group $O$ has:

• A. no antibodies
• B. no antigens
• C. A or B antibodies
• D. A or B antigens

Answer 1

Answer: (B)

Man has mainly 4 types of blood groups ${}^{\prime }{A}^{\prime \prime }{B}^{\prime }A{B}^{\prime }$ or ' $O^{\prime }{A}^{\prime }$ blood group has $A$ antigens and $b$ antibody, ${}^{\prime }{B}^{\prime }$ has $B$ antigens and a antibody, ${}^{\prime }A{B}^{\prime }$ has no antibodies but $AB$ antigens while blood group ' $O^{\prime }$ has no antigens but ' $a$ and $b$ ' antibodies. This makes ' $A{B}^{\prime }$ a universal acceptor and ' $O$ ' a universal donor.