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Question #46800
The Question
During xerarch succession, certain plant species develop an over-expressed, heavily suberized Casparian strip in their root endodermis to prevent the back-flow of water from the stele to the soil during severe drought. Which of the following represents the primary physiological trade-off of this specific anatomical adaptation?
Options
- A.
It shifts the cortical water movement entirely to the apoplast, bypassing the need for aquaporins.
- B.
It significantly increases radial hydraulic resistance, thereby decreasing the overall rate of water uptake.
- C.
It induces the active transport of water molecules across the endodermis to maintain water column continuity.
- D.
It decreases the solute potential of the pericycle, leading to an immediate loss of root pressure.
Check Your Answer
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
Casparian_Strip_Chemistry|Hydrarch_vs_Xerarch_Convergence|Root_Absorption
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that any 'adaptation' to drought strictly increases water uptake efficiency.
They fail to recognize the physiological trade-off: structures that prevent water loss (like heavy suberization) inherently increase hydraulic resistance, thereby slowing down the rate of uptake.
Additionally, Option C exploits the common misconception that plants can 'actively pump' water against a gradient, whereas water transport is strictly passive.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Casparian Strip Chemistry |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |