Biology Homeostasis PMDC Conceptual Practice
PMDC Verified Question 41 of 99
Ingesting a high-salt meal causes a temporary surge in blood sodium levels. Which regulatory mechanism is activated to restore blood sodium concentration to normal limits?
A
Positive feedback
B
Feedforward control
C
Negative feedback
D
Passive osmotic drift
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Negative feedback
Concept: Principles of homeostatic feedback loops.

Solution: Negative feedback loops detect deviations from a physiological set-point and trigger counter-regulatory responses (e.g., inhibiting aldosterone, releasing ANP, increasing thirst/water retention) to reverse the initial disruption and restore baseline levels.

Why other options are incorrect:
  • Option A (Positive feedback): Amplifies the initial stimulus, driving physiological parameters further away from set points (e.g., blood clotting cascade, childbirth labor).

  • Option B: Anticipates changes before they occur rather than responding to detected blood surges.

  • Option D: Unregulated passive movement that does not represent an active homeostatic loop.

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.

Previous Question All Homeostasis MCQs Next Question

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.

Enter Arena Sprint iOS App Android App