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Question #45470
The Question
Estrogen is a steroid hormone that classically regulates target tissues via intracellular receptors. However, the rapid mid-cycle switch of estrogen from negative to positive feedback on hypothalamic GnRH neurons involves membrane-associated receptors and a secondary messenger cascade. If a specific chemical inhibitor of adenylate cyclase is microinjected into the hypothalamus during the late follicular phase, which of the following will be the primary consequence?
Options
- A.
The pre-ovulatory LH surge will fail to occur because the non-genomic, cAMP-mediated signaling of estrogen on GnRH neurons is blocked.
- B.
Endometrial proliferation will cease immediately because estrogen requires cAMP as a secondary messenger to enter uterine cells.
- C.
Basal FSH secretion will halt because steroid hormones exclusively rely on the cAMP pathway for negative feedback.
- D.
The Graafian follicle will undergo atresia due to the direct inhibition of LH receptors on the theca interna cells.
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
Estrogen_Receptor|cAMP|GnRH|Hypothalamus
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students rigidly memorize the NCERT rule 'Steroid hormones = Intracellular receptors = No secondary messengers'.
They fail to recognize the advanced physiological exception of rapid, non-genomic steroid actions (like the estrogen-induced LH surge) which utilize membrane receptors and cAMP.
Furthermore, Option D serves as a 'Location Trap', testing if the student realizes that a hypothalamic injection will not directly inhibit ovarian receptors.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Progesterone/Estrogen Feedback |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |