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Question #45452
The Question
Angiotensin II is a potent vasoconstrictor that interacts with membrane-bound receptors on target cells to restore glomerular blood pressure (GBP). Suppose a pharmacological agent specifically hyper-activates intracellular phosphodiesterase (an enzyme that degrades cyclic AMP) in these target cells. Which of the following statements is CORRECT regarding the physiological outcome?
Options
- A.
The physiological response will be blunted because the endocrine signal is decoupled from the intracellular biochemical cascade.
- B.
Aldosterone secretion will increase normally, as the adrenal cortex relies exclusively on intracellular receptors to detect Angiotensin II.
- C.
The target cells will exhibit an exaggerated vasoconstrictive response due to the rapid accumulation of secondary messengers.
- D.
Renin secretion from the juxtaglomerular cells will immediately cease due to a direct negative feedback loop mediated by the agent.
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
RAAS_Mechanism|Hormone_Half_life_Logic|cAMP_Phosphodiesterase
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the chemical nature of a stimulating hormone (Angiotensin II, a peptide using membrane receptors and secondary messengers) and its downstream product (Aldosterone, a steroid).
The trap in Option B exploits the common misconception that hormones regulating steroid glands are themselves steroids.
Furthermore, it tests the application of secondary messenger degradation (PDE activity) on signal transduction and systemic feedback loops.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Secondary Messenger Cascade |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |