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Question #45401
The Question
An isolated mammalian population facing habitat fragmentation (a driver of the 'Evil Quartet') is exposed to waterborne endocrine disruptors. Researchers note a severe decline in birth rates because the spermatozoa fail to undergo hyperactivated motility and membrane cholesterol depletion within the female reproductive tract. Which of the following best describes the physiological block and its ecological consequence?
Options
- A.
Inhibition of Ca2+ influx and adenylate cyclase prevents capacitation, acting as a physiological reproductive barrier that exacerbates population decline.
- B.
Blockage of FSH receptors in the epididymis prevents spermiogenesis, leading to a pre-zygotic isolation barrier and co-extinction.
- C.
Suppression of the cortical reaction prevents the acrosome from releasing sperm lysins, driving the population toward over-exploitation.
- D.
Alteration of the cervical pH prevents the morphological maturation of sperm, directly causing habitat fragmentation.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Sperm Capacitation Location|Species-Area Relationship|Evil Quartet Drivers
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the locations and definitions of sperm maturation phases (Spermiogenesis vs.
Capacitation).
The prompt explicitly states the failure occurs 'within the female reproductive tract', which strictly isolates Capacitation.
The question also requires synthesizing micro-level human physiology with macro-level ecology (Biodiversity and Conservation).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Sperm Capacitation Location |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |