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Question #45374
The Question
During an In Vitro Fertilization (IVF) procedure, a batch of unfertilized human oocytes is accidentally exposed to a calcium ionophore (a chemical that artificially increases intracellular levels) prior to the introduction of capacitated sperm. Which of the following will be the most likely consequence of this exposure?
Options
- A.
Sperm-zona binding will fail due to the premature exocytosis of cortical granules and subsequent inactivation of ZP3 receptors.
- B.
The oocytes will become highly susceptible to polyspermy because the premature calcium surge depletes the cortical granules.
- C.
The approaching sperm will undergo premature acrosome reactions in the culture medium, failing to penetrate the corona radiata.
- D.
The oocytes will permanently arrest in Metaphase II, preventing the extrusion of the second polar body even if a sperm enters.
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
Oocyte_Activation|Cortical_Granules|Zona_Pellucida_Hardening
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that ' is essential for fertilization' but fail to sequence its exact role.
The trap is assuming that artificial will enhance fertilization or that depleting cortical granules leads to polyspermy.
The key is realizing that the cortical reaction's primary function is to destroy sperm receptors (ZP3); doing this prematurely creates an impenetrable 'zona block' against all sperm.
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 |