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Question #45378
The Question
A female patient with a history of recurrent early spontaneous abortions is found to have a consistently blunted Luteinizing Hormone (LH) surge, which leads to the release of an incompletely matured secondary oocyte. If fertilization occurs, which of the following cellular mechanisms best explains the subsequent embryonic lethality?
Options
- A.
Deficient exocytosis of cortical granules prevents the zona reaction, resulting in polyspermy and a polyploid zygote.
- B.
The oocyte fails to complete Meiosis II upon sperm entry, leading to the retention of the second polar body and a triploid embryo.
- C.
Inadequate LH prevents the acrosomal reaction of the sperm upon contact with the Zona Pellucida, causing syngamy failure.
- D.
Premature degradation of the corpus luteum causes a lack of progesterone, which is directly required to initiate the fast block to polyspermy.
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
Ovarian_Follicle_Stages|LH_Surge|Secondary_Oocyte
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often compartmentalize endocrinology (LH causes ovulation) and embryology (cortical reaction prevents polyspermy).
The misconception is failing to link inadequate LH-induced oocyte maturation to the structural failure of the zona reaction.
The trap options exploit confusion between the triggers for Meiosis II completion, acrosomal reaction, and the actual mechanism of polyspermy prevention.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Polyspermy Prevention Mechanisms |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |