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Question #46767
The Question
A primary spermatocyte is treated with a specific concentration of Actinomycin D that selectively targets nucleolar activity just before entering Meiosis I. Cytological observation reveals that while chromatin condensation initiates normally, the cell fails to complete the reductional division. Which of the following best explains the primary molecular reason for this meiotic arrest?
Options
- A.
The drug directly depolymerizes microtubules, preventing meiotic spindle formation despite normal protein synthesis.
- B.
Inhibition of RNA Polymerase I prevents rRNA synthesis, halting ribosome biogenesis and the de novo translation of spindle assembly proteins.
- C.
The drug inhibits RNA Polymerase II in the nucleoplasm, blocking the mRNA transcription required for the formation of the synaptonemal complex.
- D.
Suppression of RNA Polymerase III prevents tRNA synthesis, leading to a failure in translating histone proteins required for further condensation.
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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
Nucleolar Functionality|Chromatin Condensation States|Meiotic Reductional Division
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' is distinguishing the specific roles and locations of the three eukaryotic RNA polymerases (Pol I in the nucleolus for rRNA, Pol II for mRNA, Pol III for tRNA) and linking ribosomal throughput to the progression of cell division.
A common misconception is failing to differentiate between the biochemical requirements for early prophase (which can run on pre-existing proteins) versus late prophase/metaphase (which requires de novo translation for spindle assembly).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell – The Unit of Life - Class 11 |
| Concept | Nucleolar Functionality |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |