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Question #46065
The Question
A large Biosphere Reserve experiences severe habitat fragmentation in its transition zone, leading to a pronounced 'edge effect'. This facilitates the rapid colonization of an invasive alien weed. Even though forest officials strictly prevent any human or livestock entry into the core zone, the native endemic flora within the core zone begins to decline. Which of the following best explains this ecological fallout?
Options
- A.
The edge effect physically shrinks the core zone's legal boundaries, forcing endemic species into the buffer zone where they face human exploitation.
- B.
The invasive weed acts as 'biological pollution', utilizing wind or water dispersal to bypass the buffer zone and infiltrate the core zone, disrupting its function as an evolutionary refuge.
- C.
The fragmentation of the transition zone directly alters the microclimate of the core zone, converting it into an ecotone that favors pioneer invasive species over climax species.
- D.
The buffer zone loses its educational and research functions, prompting native fauna to act as vectors that carry the invasive weed's seeds outward into the transition zone.
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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
Parthenium hysterophorus|Native Flora|Specialist Pollinators
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the NCERT fact that the 'Core zone is strictly protected and undisturbed by human activity', leading to the misconception that it is completely immune to all external threats.
The trap lies in failing to distinguish between 'legal/physical protection' and 'ecological vulnerability'.
Biological pollution (invasive species dispersal) ignores legal boundaries and buffer zones, demonstrating how edge effects in outer zones can systemically compromise in-situ conservation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Alien Species Invasion Impacts |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |