Question

Explain the classical pathway of complement activation.

03 Feb 2026
Answer :
Word Count : 529
The classical pathway of complement activation is an essential part of the immune response, particularly in defending the body against infections. This pathway is triggered by the recognition of pathogens or antigen-antibody complexes, and it plays a key role in the elimination of these threats through various mechanisms like opsonization, inflammation, and cell lysis. The pathway is highly specific and involves a series of protein interactions and enzymatic activations. The classical pathway begins with the formation of the antigen-antibody complex. When an antigen, such as a pathogen, is recognized by antibodies (usually IgG or IgM), these antibodies bind to the antigen. This binding exposes a binding site on the Fc region of the antibody, which is recognized by the first component of the classical pathway, C1. C1 is a complex composed of three subunits: C1q, C1r, and C1s. Among these, C1q plays a crucial role in the initiation of the classical pathway. C1q binds to the Fc region of the antibody that is attached to the antigen. This binding
______ __________ _____ __________ _________ ______.
____ _______ _________ __________ ________ ____ ______.
___ _____ ________ _____ _____ _____ __________ ________ _________ __________.
_________ ______ __________ _____ _______ _______ ________ _____ ____ ______ ____ ___.
__________ _________ ____ ______ _________ _______ _____ ______ _________.
________ ______ ________ _______ _________ ___ _______ _______ _________ ____ __________ _____.
_____ ________ ________ ______ _________ ________ ______ _______ ___ _____.
__________ ______ ____ ________ ___ _____ ______.
____ ______ ________ _________ _____ _______ _________ __________ ____ ________ _________ __________.
________ ______ _________ ______ _______ ________ __________ _______ _______ ________ _________.
____ __________ _______ __________ ______ __________ ______.
________ _______ ___ ________ ________.
____ ___ _____ _________ ____ ___ _____ ____ ________ _____ _______.
_________ _________ ____ ___ ____ _________ _________.
______ _______ _______ ________ _________.
___ __________ _______ ___ ______ ______ ____ ___ _____ ____.
_________ ___ ____ _________ ______ _____ ___ ___ ________ _____.
________ ____ ____ _____ __________ _________ _____ _______.
_______ _____ ____ _____ _______.
____ ____ ____ ____ __________ ___ _______ _________ ________.
_________ __________ ___ _____ ____ ____ _______ ___ ____ _________ ___.
____ _________ _________ _______ ________ ________ ______.
__________ _________ __________ ________ ____ ______ _____ __________.
_____ _____ ____ ________ _______ ___ ______ ___ ___ ___.
___ __________ _________ _______ ___ _____.
__________ ____ ______ _________ ____ ___.
____ __________ ________ _________ ______ _____ ______.
__________ __________ __________ ___ ____.
_________ _____ _____ __________ __________ _________ ________.
_______ ___ ___ ___ _________ ____ __________.
_________ ____ _________ _____ _______.
__________ ________ _______ ________ ____ _________.
_________ ___ ____ ________ ___ _____ ______ _________.
______ _________ _____ ________ ____.
_____ __________ __________ _________ _____ ______ ____ ___ _____.
_________ ____ ______ _____ _____ _______ __________ _____.
______ ___ ____ _________ ____ ______ __________ ___ ______.
______ _______ ____ _____ __________ _______.
____ ______ ________ _______ _______ ____ ___ ____ __________ ____ _________.
______ _____ ___ _________ ______ ________ ___ _____.
______ ___ ______ __________ ______ _______ ________ ________.
______ _________ _________ ______ ___ ________ _______ ________ _______ _________.
__________ ______ __________ ____ __________ _________ _____ __________.
___ ________ _____ _______ __________ ______.
___ ______ _______ _____ _____ ________.
IGNOU ACADEMY
Your IGNOU journey, made easier.
  • Solved Assignments
  • Study Notes
  • Guess Papers
  • Question Papers
Skip in 10
Top
📞
Call Support Instant phone assistance IGNOU BBCCT 127 2026 - Explain the classical pathway of complement activation. | IGNOU Academy
→
🟢
WhatsApp Chat Fast live messaging
→
Email Us Business enquiries & support
→