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Question #45272
The Question
In human oogenesis, primary oocytes undergo a prolonged arrest in the diplotene stage of Prophase I. Which of the following best explains the structural state of the chromosomes during this arrest and the clinical consequence if the transition to diakinesis fails upon the resumption of meiosis?
Options
- A.
Homologous chromosomes are held together by the synaptonemal complex; failure of its dissolution during the pre-ovulatory surge leads to polyploidy.
- B.
Sister chromatids are held together at the centromere; premature splitting of the centromere prior to ovulation leads to monosomy in all resulting gametes.
- C.
Homologous chromosomes remain tethered at chiasmata; failure of terminalization during the pre-ovulatory surge leads to non-disjunction and aneuploidy.
- D.
Bivalents remain attached to the nuclear envelope; failure of nuclear envelope breakdown leads to complete meiotic arrest and primary amenorrhea.
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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
Terminalization of Chiasmata|Meiotic Arrest Points|Oogenesis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the specific structures holding chromosomes together at different meiotic stages (Synaptonemal complex in Pachytene vs.
Chiasmata in Diplotene).
Additionally, there is a common misconception conflating 'Aneuploidy' (gain/loss of a single chromosome) with 'Polyploidy' (gain of an entire set).
This question synthesizes NCERT Class 11 Cell Cycle (terminalization of chiasmata), Class 12 Human Reproduction (diplotene arrest), and Class 12 Genetics (chromosomal disorders).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | Terminalization of Chiasmata |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |