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Question #46071
The Question
A strictly protected in-situ biodiversity hotspot, characterized by high endemism, undergoes a massive invasion by an alien weed species. According to the principles of the 'Evil Quartet' and the Species-Area relationship (log S = log C + Z log A), which of the following represents the most accurate systemic fallout for the native taxonomic groups within this protected fragment?
Options
- A.
The Z-value for native species will disproportionately increase (steepen) as competitive exclusion effectively shrinks their functional area, accelerating local extinctions.
- B.
The Z-value will remain constant between 0.1 and 0.2 because in-situ conservation legally protects the absolute geographical area (A) of the hotspot.
- C.
The Z-value will decrease (flatten) as the introduction of the alien species adds to the total species richness (S) of the protected fragment.
- D.
The native species will experience co-extinction, causing the Z-value to shift to the range of 0.6 to 1.2, which is typical for small, disturbed fragments.
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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
IUCN Red List|Endemic Flora|Specialized Herbivores
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that Z-values are 'constant (0.1-0.2)' for small areas and 'steep (0.6-1.2)' for continents.
They fail to realize that the Z-value is a dynamic ecological slope representing the rate of species accumulation/loss.
An invasive species acts as a biological area-reducer (niche usurper), steepening the slope (increasing Z) for native species because they are lost at a much higher rate within the same physical area.
The trap in Option D exploits the rote memorization of the '0.6-1.2' data point by misapplying its geographical context.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Co-extinction Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |