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Question #45756
The Question
The Kangaroo rat of North American deserts exhibits remarkable ecological fitness in xeric biomes due to directional selection favoring extreme water conservation. Regarding its osmoregulatory adaptations and the counter-current mechanism, which of the following statements is INCORRECT?
Options
- A.
Directional selection in xeric biomes shifts the population phenotype towards a higher frequency of juxtamedullary nephrons with exceptionally long Loops of Henle.
- B.
To maximize the counter-current multiplier effect, the descending limb of the Loop of Henle actively transports NaCl into the inner medullary interstitium.
- C.
Elevated plasma osmolarity triggers osmoreceptors, stimulating the neurohypophysis to release Vasopressin for facultative water reabsorption in the distal tubules.
- D.
The Darwinian fitness of these rodents is augmented by their ability to utilize metabolic water generated as a byproduct of internal fat oxidation.
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
Diuretic Dynamics|Ecological Fitness|Natural Selection Directionality
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the specific permeabilities of the descending and ascending limbs of the Loop of Henle.
The trap relies on cognitive overload; by wrapping the question in complex evolutionary terminology (directional selection, Darwinian fitness, xeric biomes), the student's attention is drawn away from the fundamental physiological error in Option B (assigning NaCl transport to the descending limb instead of the ascending limb).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Diuretic Dynamics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |