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Question #47679
The Question
Two closely related plant species, Species X and Species Y, inhabit a phosphorus-deficient ecosystem. Species X forms an obligate mutualistic association with the fungal genus Glomus, whereas Species Y relies solely on its dense root hair network. Despite phosphorus being a severely limiting resource, both species coexist indefinitely. Which of the following statements regarding this ecological dynamic is INCORRECT?
Options
- A.
The fungal hyphae allow Species X to absorb phosphorus beyond the immediate root depletion zone, demonstrating spatial resource partitioning.
- B.
The mutualistic interaction shifts the realized niche of Species X, thereby mitigating direct interspecific competition with Species Y.
- C.
Coexistence is achieved because the mycorrhizal network fixes atmospheric phosphorus, eliminating the resource limitation for both species.
- D.
This scenario avoids Gause's Competitive Exclusion Principle because the biotic interaction alters Species X's primary zone of nutrient acquisition.
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
Fungal_Hyphae|Rhizosphere|Resource_Partitioning
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' relies on a dual trap: integrating Population Interactions (Competition vs.
Mutualism) with Ecosystem Nutrient Cycling.
Students frequently associate symbiotic microbes with 'atmospheric fixation' due to the overemphasis on Rhizobium-Nitrogen dynamics.
By swapping Nitrogen for Phosphorus, the trap exploits the failure to recall that the Phosphorus cycle is strictly sedimentary (NCERT Class 12, Ch 14), making 'atmospheric phosphorus fixation' biologically impossible.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Mycorrhiza Nutrient Dynamics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |