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Question #47471
The Question
A patient with a parathyroid adenoma secretes abnormally high, sustained levels of Parathyroid Hormone (PTH). Over time, the target cells in the renal tubules exhibit a diminished physiological response to the hormone, despite its high concentration in the blood. Based on the mechanism of action of peptide hormones, which of the following is the primary molecular cause for this target cell desensitization?
Options
- A.
Internalization and downregulation of membrane-bound receptors to prevent excessive second messenger generation.
- B.
Depletion of the intracellular hormone-receptor complex required for direct gene transcription.
- C.
Rapid enzymatic degradation of the hormone at the receptor site, mimicking synaptic neurotransmitter clearance.
- D.
Inhibition of the hormone-receptor complex from crossing the nuclear membrane to alter gene expression.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Neurotransmitter Receptor Specificity|Hormone Half-life Logic|Calcium Homeostasis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Differentiating the kinetics and regulatory mechanisms of endocrine signaling (receptor downregulation) from synaptic signaling (rapid enzymatic clearance), while simultaneously testing the NCERT classification of hormone receptor locations (peptide vs. steroid).
Students often fail to recognize that target cells actively modulate their receptor density in response to chronic hormone exposure, and frequently confuse the mechanisms of water-soluble versus lipid-soluble hormones.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Neurotransmitter Receptor Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |