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Question #47420
The Question
In a neurobiology experiment, a researcher introduces a specific double-stranded RNA (dsRNA) into a mammalian neuron. This dsRNA is perfectly complementary to the mRNA encoding the voltage-gated sodium channels (VGSCs) of the axolemma. Assuming the RNA interference (RNAi) pathway is fully activated, what will be the most likely electrophysiological consequence when a suprathreshold stimulus is applied to this neuron?
Options
- A.
The RISC complex will inhibit the transcription of the VGSC gene, preventing the neuron from maintaining its resting membrane potential.
- B.
Post-transcriptional gene silencing will reduce VGSC density, allowing only graded potentials but preventing the rapid depolarization phase of an action potential.
- C.
The dsRNA will bind directly to the axolemma, blocking the existing VGSCs and locking the neuron in a permanently hyperpolarized state.
- D.
Translation of VGSCs will halt, causing the threshold potential to become more negative and resulting in continuous, spontaneous action potentials.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
dsRNA|RISC_complex|Voltage_Gated_Channels
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question bridges Biotechnology (RNAi mechanism as PTGS) with Neural Coordination (the specific role of VGSCs in the depolarization phase vs.
RMP maintenance).
The trap relies on students confusing the roles of different ion channels (assuming VGSCs maintain the resting membrane potential) or misunderstanding RNAi as a direct protein inhibitor or transcriptional blocker rather than an mRNA degrader.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Action Potential Threshold Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |