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Question #46827
The Question
An invasive alien pathogen secretes a specific toxin that completely inhibits the dedifferentiation of outer cortical cells in the dicotyledonous trees of a late-seral forest community. Which of the following represents the most accurate anatomical consequence and its subsequent ecological impact?
Options
- A.
The phellogen fails to develop, halting the formation of the periderm; the trees become highly susceptible to mechanical injury and infections, leading to premature mortality and destabilization of the climax community.
- B.
The interfascicular cambium cannot form, preventing the formation of a continuous cambial ring; secondary xylem production ceases, causing the ecosystem to revert to a pioneer stage.
- C.
The phelloderm loses its meristematic activity, failing to produce suberized phellem cells; the resulting severe water loss shifts the mesarch succession towards a xerarch climax.
- D.
The vascular cambium fails to produce secondary phloem, starving the roots; the dominant trees die, allowing shade-intolerant pioneer species to immediately establish a new climax community.
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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
Phellogen|Phellem|Ecological Succession Climax|Secondary Meristems
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question tests the student's ability to precisely identify the cellular origin of lateral meristems (extrastelar phellogen from the cortex vs. intrastelar interfascicular cambium from medullary rays) and synthesize this micro-anatomical fact with macro-ecological succession dynamics.
A common misconception is confusing the roles and origins of the two cambial rings, as well as misunderstanding that phelloderm is a product of secondary growth, not a meristem itself.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Periderm Components |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |