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Question #45812
The Question
A loss-of-function mutation in the gene encoding the Luteinizing Hormone (LH) receptor manifests pleiotropic effects in a human male. Based on the integration of the Hypothalamic-Pituitary-Gonadal (HPG) axis, which of the following accurately describes the physiological cascade resulting from this mutation?
Options
- A.
Failure of Leydig cells to synthesize androgens, leading to both arrested spermatogenesis and a lack of secondary sexual characters.
- B.
Inability of Sertoli cells to secrete Androgen Binding Protein (ABP), causing a direct failure in the meiotic division of primary spermatocytes.
- C.
Hypersecretion of testosterone due to the loss of negative feedback on the hypothalamus, resulting in premature puberty.
- D.
Complete cessation of GnRH release from the anterior pituitary due to the absence of circulating androgens.
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
GnRH|FSH_LH|Feedback_Loops
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the specific cellular targets of gonadotropins (LH targets Leydig cells; FSH targets Sertoli cells) and misinterpret negative feedback loops.
The trap in Option D relies on a location error (GnRH is hypothalamic, not pituitary) and a functional error (low hormones stimulate, rather than inhibit, releasing hormones).
Option C tests the understanding that receptor failure prevents hormone production regardless of upstream signals.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Principles of Inheritance and Variation - Class 12 |
| Concept | Pleiotropy Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |