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Question #46542
The Question
In an attempt to suppress a specific oncogene, researchers used a viral vector to introduce DNA that produces both sense and antisense RNA in human cells, aiming to initiate RNA interference (RNAi). However, the therapy resulted in widespread apoptosis of healthy, non-cancerous cells. Which of the following best explains this unintended consequence?
Options
- A.
The sense and antisense RNA failed to form dsRNA, causing the RISC complex to randomly degrade endogenous mRNAs.
- B.
The siRNA generated by Dicer exhibited partial sequence homology with transcripts of essential survival genes, leading to their unintended cleavage by RISC.
- C.
The viral vector induced RNA-dependent RNA polymerase, which amplified the oncogene transcripts instead of silencing them.
- D.
The dsRNA directly bound to the promoter region of the oncogene, causing Transcriptional Gene Silencing (TGS) instead of Post-Transcriptional Gene Silencing (PTGS).
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
RNA Interference (RNAi) Mechanism|Oncogenes vs Proto-oncogenes|Transgenic Animal Purpose
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume RNAi is 100% specific because NCERT mentions 'silencing of a specific mRNA'.
The trap tests the understanding that specificity relies on sequence homology.
Because siRNAs are short, they can inadvertently match other essential mRNAs (off-target effects), which is a major real-world hurdle in gene therapy.
It bridges the NCERT concept of RNAi with the clinical reality of off-target apoptosis.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Oncogenes vs Proto-oncogenes |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |