Complement attaches to immunoglobulin at ?
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.
Aminoterminal
Fab region
Variable region
Fc fragment