Biology Nervous Coordination SZABMU 2023
PMDC Verified Question 42 of 86
GABA is an example of:
A
Enzyme
B
Inhibitory neurotransmitter
C
Excitatory neurotransmitter
D
Hormone
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Inhibitory neurotransmitter
Concept:

Neurotransmitters can either encourage a neuron to fire (excitatory) or prevent it from firing (inhibitory).

Solution:

  • GABA (Gamma-Aminobutyric Acid) is the primary inhibitory neurotransmitter in the human central nervous system. It works by opening chloride channels, causing hyperpolarization and making it harder for the postsynaptic neuron to reach action potential threshold.


Why other options are incorrect:

  • Excitatory: Glutamate is the main excitatory neurotransmitter, performing the opposite function of GABA.


  • Enzyme / Hormone: GABA is an amino acid derivative acting as a local synaptic messenger, not a systemic hormone or catalyst.

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 Nervous Coordination 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