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Question #45746
The Question
A patient presents with severe polyuria and polydipsia. Blood analysis reveals normal levels of Antidiuretic Hormone (ADH) and normal hepatic nitrogen metabolism. A renal biopsy indicates a genetic defect in the collecting duct cells that completely blocks the cAMP-dependent secondary messenger cascade. Which of the following statements regarding this patient's physiological state is INCORRECT?
Options
- A.
The collecting duct remains impermeable to water due to the failure of Aquaporin-2 (AQP-2) translocation to the apical membrane.
- B.
The osmolarity of the inner medullary interstitium decreases due to the failure of ADH-mediated urea recycling.
- C.
The patient will develop severe uremia because the blocked cascade prevents the active secretion of urea into the distal convoluted tubule.
- D.
Cell-mediated immunity remains unaffected, as thymosin signaling is highly specific and independent of this renal cascade.
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
cAMP|Protein_Kinase_A|Collecting_Duct_Aquaporins
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse 'Urea Recycling' (which maintains the osmotic gradient in the medulla) with 'Urea Excretion' (which prevents uremia).
The question also utilizes a Location Trap (falsely claiming urea is actively secreted in the DCT) and introduces Thymosin as a functional distractor to test the student's ability to confidently isolate unrelated endocrine systems.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Urea Recycling |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |