Which one of the following immunoglobulins constitues the antigen binding component of B-cell receptor -: (A) IgA, (B) IgD, (C) IgM, (D) IgG
Answer is B. The BCR is composed of surface-bound IgD or IgM antibodies and associated Ig-a and Ig-b heterodimers, which are capable of signal transduction Reff: www.mayoclinic.com