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Question #47413
The Question
A skeletal muscle preparation is treated with a neurotoxin that acts as a competitive inhibitor of nicotinic acetylcholine receptors at the neuromuscular junction. Which of the following accurately describes the physiological consequence on the muscle fiber?
Options
- A.
The resting membrane potential (RMP) is abolished due to the inhibition of the Na+/K+ ATPase pump, resulting in flaccid paralysis.
- B.
The RMP is maintained, but the muscle undergoes flaccid paralysis because ligand-gated sodium channels fail to open, preventing an end-plate potential.
- C.
The muscle undergoes sustained tetanic contraction because the toxin prevents the repolarization of the sarcolemma.
- D.
The RMP becomes hyperpolarized due to the continuous opening of voltage-gated potassium channels, blocking signal transduction.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Na+/K+ ATPase|Ligand-gated channels|Curare
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the maintenance of the resting membrane potential (active transport via Na+/K+ pumps) and the initiation of an action potential (ligand-gated channels).
Students often mistakenly assume that paralysis implies a collapse of the RMP.
The trap forces the realization that signal transduction failure at the synapse does not equate to ionic gradient failure.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Resting Membrane Potential Ionic Flux |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |