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Question #45440
The Question
A patient presents with chronic hypotension, severe salt-wasting (high urine ), and hyperkalemia. Blood tests reveal abnormally elevated levels of Renin, Angiotensin II, and Aldosterone. Based on the principles of chemical coordination and the RAAS pathway, which of the following molecular defects best explains this physiological paradox?
Options
- A.
Mutation in the membrane-bound receptors for aldosterone in the distal convoluted tubule and collecting duct.
- B.
Defective intracellular mineralocorticoid receptors preventing the transcription of proteins required for reabsorption.
- C.
Hypersecretion of Atrial Natriuretic Factor (ANF) causing direct stimulation of the juxtaglomerular apparatus.
- D.
Failure of the macula densa cells to detect low tubular concentration, leading to continuous RAAS activation.
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
Adrenal_Cortex|Mineralocorticoid_Receptors|Aldosterone
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Excretory System (RAAS) with Chemical Coordination (Mechanism of Hormone Action).
The primary trap is Option A, which tests the student's ability to recall that steroid hormones (like aldosterone) act via intracellular receptors, not membrane-bound receptors.
It also tests the negative feedback loop: target tissue insensitivity leads to a compensatory, yet futile, overproduction of RAAS hormones.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | RAAS Mechanism |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |