Complement attaches to immunoglobulin at ?: (A) Aminoterminal, (B) Fab region, (C) Variable region, (D) Fc fragment
Answer is D. Ans. is 'd' i.e., Fc fragment . Fc fragment is composed of the carboxyterminal. It determines the biological activity such as complement fixation, placental transfer, skin fixation and catabolic rate. CH-2 of Ig G and CH, of IgM bind to C1q poion of CI.