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Question #46736
The Question
Adrenocorticotropic hormone (ACTH) acts on the adrenal cortex via membrane-bound receptors, utilizing cAMP as a secondary messenger. If a targeted mutation in the cells of the zona fasciculata completely disrupts their endosomal sorting and receptor internalization machinery, which of the following physiological outcomes is most likely to occur upon continuous ACTH stimulation?
Options
- A.
The hormone-receptor complex will translocate to the nucleus to directly regulate gene expression.
- B.
There will be a prolonged secondary messenger cascade, mimicking a tumorigenic state of hypercortisolism.
- C.
The generation of cAMP will be completely inhibited due to the inability to form hormone-receptor endosomes.
- D.
The adrenal cortex will undergo rapid atrophy due to the loss of negative feedback inhibition.
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
Adrenal_Cortex_Hormones|Endosomes|Receptor_Downregulation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often misunderstand the role of receptor internalization in peptide hormone signaling.
A common misconception is that membrane-bound receptors must be internalized to initiate a response, whereas internalization is primarily a mechanism for receptor downregulation and signal termination.
Failing to recognize this leads to the incorrect assumption that blocking endocytosis stops the signal, rather than prolonging it.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell – The Unit of Life - Class 11 |
| Concept | Endomembrane System Connectivity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |