Complement proteins
A) kill pathogenic cells directly or mark them for subsequent phagocytosis.
B) are the precursor molecules that eventually become antibodies.
C) provide a protective covering on healthy cells that redirects any macrophage that may be inappropriately targeting it.
D) attach directly to the antigens on the surface of a pathogen.

Question

Quizplus · Accepted Answer

Complement proteins can kill pathogenic cells directly by creating holes in their cell membranes or marking them for subsequent phagocytosis by cells of the immune system. They do not become antibodies and do not provide a protective covering on healthy cells. While they do attach directly to antigens on the surface of a pathogen, this is not their only function.

Complement Proteins