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Question #46034
The Question
Severe anthropogenic habitat fragmentation in a continuous tropical rainforest transforms it into isolated patches. Ecologists analyzing the species-area relationship across this fragmented landscape note that the regression coefficient (Z-value) has shifted from 0.15 to 0.75. According to Alexander von Humboldt’s model and the 'Evil Quartet' of biodiversity loss, what does this steepened slope signify, and what will most likely drive the subsequent wave of secondary extinctions?
Options
- A.
It signifies that species richness decreases drastically with a reduction in area; secondary extinctions will be driven by co-extinctions of obligate mutualists.
- B.
It signifies that the ecosystem has assumed the diversity patterns of a temperate latitude; secondary extinctions will be driven by alien species invasions.
- C.
It signifies that species richness has become independent of the habitat area; secondary extinctions will be driven by over-exploitation of edge species.
- D.
It signifies an overall increase in species richness due to new niche formation; secondary extinctions will be driven by competitive exclusion.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Secondary Productivity|Nutrient Cycling Reservoirs
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Understanding the mathematical implication of the Z-value.
Students often memorize the NCERT data points (0.1-0.2 for normal areas vs 0.6-1.2 for continents) but fail to grasp that a steeper slope (higher Z) means a higher vulnerability to area loss.
Furthermore, linking the primary driver (Habitat Fragmentation) to its inevitable secondary consequence (Co-extinctions) tests true NCERT-Plus synthesis.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Standing Crop quantification |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |