Question

The complement pathway that requires antibodies to be activated is the _________.

1) alternate pathway
2) classical pathway
3) properdin pathway
4) inflammatory pathway

Answer 1

The classical pathway is activated by the presence of antibodies and initiates the complement system response, leading to the destruction of pathogens.

Step-by-step explanation:

The complement pathway that requires antibodies to be activated is the classical pathway. In this pathway, the complement system gets activated when C1 binds to an antigen-antibody complex on the surface of an invading pathogen. This activation leads to a cascade of events where complement components C2 and C4 split and eventually help to form damaging pores in the plasma membrane of the pathogen. The alternative pathway, on the other hand, can be activated spontaneously and does not require antibodies for activation. It involves the breakdown of C3 convertase and is regulated to prevent host cells from being attacked.