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Question #45866
The Question
In an experiment synthesizing the principles of the Hershey-Chase study and RNA interference (RNAi), a DNA virus infects a transgenic eukaryotic host. The host genome contains an integrated vector expressing dsRNA strictly homologous to the viral major capsid protein gene. Post-infection, the host is cultured in a medium containing radioactive 35S and 32P. Which of the following is the most scientifically accurate outcome regarding the intracellular synthesis of viral progeny?
Options
- A.
The RISC complex will directly degrade the invading viral dsDNA, preventing the incorporation of both 32P and 35S.
- B.
Viral DNA will replicate and incorporate 32P, but 35S-labeled progeny capsids will fail to assemble due to mRNA cleavage.
- C.
35S will be incorporated into the newly transcribed viral mRNA, but its translation will be competitively inhibited by the Dicer enzyme.
- D.
Fully assembled progeny virions will contain 35S-labeled capsids because RNAi vectors only silence endogenous host genes, not exogenous viral genes.
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
T2_Bacteriophage|P32_S35_Labeling|RISC_Complex
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students must distinguish between replicational events (DNA synthesis) and post-transcriptional events (mRNA translation).
The trap lies in assuming RNAi halts the entire viral life cycle at the DNA level (like a restriction enzyme) rather than specifically blocking protein synthesis.
It also tests the fundamental NCERT fact from the Hershey-Chase experiment that 35S exclusively labels proteins, making Option C a powerful distractor for those who misread chemical specificities.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Molecular Basis of Inheritance - Class 12 |
| Concept | Hershey-Chase Isotopic Labeling |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |