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Question #45238
The Question
Telomeric DNA in eukaryotes consists of tandem repeats of G-rich sequences that can form non-canonical secondary structures known as G-quadruplexes. If a novel chemotherapeutic drug specifically hyper-stabilizes these G-quadruplex structures in a rapidly dividing cancer cell line, which of the following is the most likely immediate consequence leading to premature cellular senescence?
Options
- A.
The telomeres undergo rapid elongation, causing the cell to bypass the G0 phase and undergo uncontrolled mitotic divisions.
- B.
The structural stabilization prevents telomere uncapping, thereby hiding the chromosome ends from DNA repair enzymes and promoting immortality.
- C.
The stabilized structures disrupt the protective telomere cap, mimicking a double-strand DNA break and triggering a p53-mediated cell cycle arrest.
- D.
The drug binds to the centromeric heterochromatin, preventing spindle fiber attachment and arresting the cell in Metaphase.
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
Telomerase|G-quadruplexes|Senescence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that 'stabilizing' a DNA structure at the telomere would increase its protective function and promote cell longevity.
The trap (Option B) plays on this misconception.
In reality, hyper-stabilizing the G-quadruplex prevents the dynamic remodeling required for normal telomere capping and telomerase binding, leading the cell to perceive the chromosome end as broken DNA.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biomolecules - Class 11 |
| Concept | Nucleic Acid Structural Stability |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |