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Question #45304
The Question
The forelimbs of Homo sapiens, bats, and whales exhibit a conserved anatomical blueprint but have undergone divergent evolution to perform different functions. The raw genetic variation driving this divergence is primarily generated during gametogenesis. Which of the following statements regarding the specific meiotic event responsible for this variation is INCORRECT?
Options
- A.
It occurs during the pachytene stage of Prophase I, which is cytologically characterized by the appearance of recombination nodules.
- B.
It involves the enzyme-mediated exchange of genetic material between sister chromatids of homologous chromosomes.
- C.
By breaking the linkage between genes on the same chromosome, it generates the novel allelic combinations required for divergent evolution.
- D.
The process utilizes the recombinase enzyme complex to shuffle conserved ancestral DNA sequences, providing the substrate for natural selection.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Pachytene|Homologous Organ Ancestry|Chiasmata_Formation
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' relies on cognitive overload.
The question heavily frames the scenario using evolutionary concepts (homologous organs, divergent evolution, conserved blueprints) to distract the student from a fundamental cytological micro-terminology trap: the distinction between 'sister' and 'non-sister' chromatids during Pachytene crossing over.
Students failing to read every word carefully will assume Option B is a generic true statement about crossing over and miss the fatal flaw.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | Pachytene Crossing Over |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |