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Question #46078
The Question
A contiguous biosphere reserve is fragmented by a network of roads, drastically increasing the perimeter-to-area ratio of the forest patches. Subsequently, a K-selected, deep-forest orchid species begins to face local extinction, even in patches where its immediate physical habitat remains untouched. Which of the following best explains this phenomenon by linking two components of the 'Evil Quartet'?
Options
- A.
Habitat fragmentation increases the 'Edge Effect', altering the microclimate and eliminating the orchid's specific pollinator, resulting in co-extinction.
- B.
Over-exploitation of the forest edge resources forces generalist herbivores into the core, leading to the competitive exclusion of the orchid.
- C.
Alien species invasion at the fragmented edges increases the core's ambient temperature, causing the orchid to die due to thermal stress.
- D.
The reduction in total area directly induces a genetic bottleneck, causing the orchid's extinction through inbreeding depression before co-extinction can occur.
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
In-situ Conservation (Hotspots)|Diversity-Stability Relationship|Nutrient Cycling Reservoirs
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often isolate the four causes of biodiversity loss (The Evil Quartet).
This question forces the synthesis of 'Habitat Fragmentation' (which creates the Edge Effect) with 'Co-extinction' (the secondary cascade).
The trap is assuming fragmentation only kills by directly removing physical space or causing immediate genetic bottlenecks (Option D), ignoring the rapid ecological uncoupling of obligate mutualisms.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | In-situ Conservation (Hotspots) |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |