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Question #46805
The Question
In an evolutionary arms race, a root-infecting pathogen evolves the ability to enzymatically degrade the Casparian strips in a dicot host to access the nutrient-rich stele. Which of the following represents the most accurate physiological and anatomical consequence of this structural breach?
Options
- A.
The apoplastic pathway becomes the sole mechanism for water transport into the pericycle, bypassing the symplast entirely.
- B.
The endodermis loses its ability to act as a biological check-post, leading to the unregulated entry of solutes into the vascular cylinder.
- C.
The active transport of mineral ions into the stele increases exponentially to compensate for the sudden loss of root pressure.
- D.
The structural integrity of the stele collapses immediately because the endodermis, which is its outermost layer, has been destroyed.
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
Stele|Endodermis|Casparian_Strip
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question tests the exact physiological role of the Casparian strip (forcing apoplastic flow into the selectively permeable symplast) and the anatomical boundaries of the stele.
Students often fall for Option D by mistakenly including the endodermis as part of the stele, or misunderstand that the Casparian strip's primary role is selective regulation ('check-post'), not just stopping water.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Stele Definition |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |