Which of the following complement component can be activated in both common as well as alternate pathways?: (A) C1, (B) C2, (C) C3, (D) C4
Answer is C. The complement proteins can be activated by 3 pathways;
Classical,lectin and alternate pathways. Terminal pathway is common to the first three pathways and is present ar the level of the post-activation stage of C3. It eventually leads to the membrane attack complex that lyses cells.