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Question #46714
The Question
Prions are infectious proteinaceous particles responsible for neurodegenerative disorders such as Bovine Spongiform Encephalopathy (BSE). In the context of cellular metabolic autonomy and the Central Dogma, which of the following statements regarding prions is INCORRECT?
Options
- A.
They bypass the Central Dogma of molecular biology, as their propagation relies on post-translational conformational changes rather than nucleic acid-directed synthesis.
- B.
The infectious isoform (PrP^Sc) acts as a conformational template that alters the secondary and tertiary structure of the normal cellular protein (PrP^c) without altering its primary amino acid sequence.
- C.
They hijack the host's translational machinery by acting as competitive inhibitors of normal mRNA, directing ribosomes to synthesize the abnormally folded PrP^Sc proteins.
- D.
They represent a distinct exception to the Cell Theory because they lack cellular organization and metabolic autonomy, yet successfully propagate within a host.
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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
Competitive Enzyme Inhibition Kinetics|Prions|Cell Theory Exceptions
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently conflate the viral mechanism of infection (hijacking host ribosomes via viral mRNA/RNA) with the prion mechanism.
Failing to recognize that prions are entirely devoid of nucleic acids leads to the misconception that they influence translation, whereas their pathogenic mechanism is exclusively a post-translational conformational templating of existing host proteins.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell – The Unit of Life - Class 11 |
| Concept | Cell Theory Exceptions |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |