Biology Immunity PMDC Conceptual Practice
PMDC Verified Question 50 of 99
A standard monomeric antibody molecule is composed of a total of how many polypeptide chains?
A
4
B
2
C
6
D
8
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: 4
Concept: Stoichiometry of antibody polypeptide chains.

Solution: A monomeric immunoglobulin is a heterotetramer consisting of 4 polypeptide chains: two identical heavy (H) chains and two identical light (L) chains (\(\text{H}_2\text{L}_2\)).

Why other options are incorrect:
  • Option B: 2 chains would form only a single heavy-light heterodimer.

  • Option C & Option D: These higher numbers describe multimeric complexes (like dimeric \(\text{IgA}\) or pentameric \(\text{IgM}\)), not a monomer.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.