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Question #46554
The Question
Researchers introduce a specific double-stranded RNA (dsRNA) into the central nervous system of an animal model. This dsRNA is perfectly complementary to the mRNA transcript of the primary receptor that binds the active alkaloid extracted from Papaver somniferum. Which of the following best describes the physiological outcome and its underlying molecular mechanism?
Options
- A.
The animal becomes desensitized to morphine because the dsRNA directly binds to the receptors in the synaptic cleft, acting as a competitive antagonist.
- B.
The animal exhibits reduced sensitivity to heroin because the intervention induces post-transcriptional silencing, decreasing receptor density on the post-synaptic membrane.
- C.
The animal becomes refractory to cocaine because the RISC complex degrades the mRNA, preventing the synthesis of dopamine reuptake transporters.
- D.
The animal shows heightened sensitivity to opioids because the dsRNA inhibits the transcriptional silencing of endogenous endorphin genes in the nucleus.
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
Opioids|RNA Interference (RNAi) Mechanism|Receptor Expression
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question bridges Biotechnology (RNAi mechanism) with Human Health and Disease (Drug-receptor interactions).
The primary trap relies on students confusing the intracellular site of action of RNAi (mRNA degradation) with extracellular pharmacological antagonism (receptor blocking in the synaptic cleft).
Secondary traps include confusing the source plants of different drugs (Poppy vs.
Coca) and failing to distinguish between transcriptional and post-transcriptional silencing.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Opioids/Cannabinoids/Coca Alkaloids |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |