<prompt> Classical complement activated by:C1C3 ConveaselgAAg - Ab complex  <response>: Antigen-antibody complex lead to activation of classical complement pathway. MAC - Membrane attack complex C5 - C9 MAC-attack on Antigen make pores and finally antigen killed Alternate Complement pathway - staing from C3QQ Note : - Compliment 1,4,2 is by passed Lectin pathway sta from C4 C1 will not be consumed in lectin pathway 