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Question #46413
The Question
A large portion of the human genome consists of repetitive DNA sequences. Under severe environmental stress, a specific class of these repetitive elements is observed to mobilize and insert into a functional exon of a tumor suppressor gene, causing insertional mutagenesis. Which of the following statements correctly identifies the nature of this element and its mechanism of mobilization?
Options
- A.
It is a retrotransposon that mobilized via an RNA intermediate using reverse transcriptase, proving that repetitive DNA plays a role in chromosome dynamics and evolution.
- B.
It is a segment of satellite DNA that excised itself using restriction endonucleases, indicating that repetitive sequences directly code for stress-response proteins.
- C.
It is a transposable element that replicated via DNA polymerase and inserted into the exon specifically to prevent the translation of mutated proteins.
- D.
It is a VNTR (Variable Number of Tandem Repeat) sequence that mobilized through homologous recombination, demonstrating its primary role in maintaining telomere length.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Retrotransposons|Reverse Transcriptase|Genome Integrity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize repetitive DNA solely in the context of DNA fingerprinting (Satellite DNA/VNTRs) and dismiss it as static 'junk'.
This question tests the NCERT-Plus synthesis that repetitive DNA includes transposable elements (retrotransposons) which are highly dynamic, utilize reverse transcriptase, and drive evolutionary changes or insertional mutagenesis when epigenetically de-repressed by stress.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Molecular Basis of Inheritance - Class 12 |
| Concept | Human Genome Repetitive DNA |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |