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Question #45389
The Question
During the first trimester of pregnancy, a patient suffers an early miscarriage. Histological analysis reveals a highly dysfunctional syncytiotrophoblast. Which of the following best explains the sequential hormonal fallout that led to the termination of this pregnancy?
Options
- A.
Inadequate hCG secretion → Degeneration of the corpus luteum → Sharp decline in progesterone → Loss of negative feedback on the hypothalamus → Initiation of a new follicular phase.
- B.
Inadequate hPL secretion → Failure of corpus luteum rescue → Decline in estrogen → Positive feedback on the anterior pituitary → Premature LH surge.
- C.
Inadequate hCG secretion → Direct sloughing of the endometrium → Secondary decline in progesterone → Release of negative feedback on GnRH.
- D.
Inadequate progesterone secretion directly from the syncytiotrophoblast → Degeneration of the corpus luteum → Loss of negative feedback on FSH → Menstruation.
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
Corpus_Luteum|hCG|Progesterone|Feedback_Loops
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the direct versus indirect roles of placental hormones.
While they know progesterone maintains the pregnancy, they frequently fail to sequence the first-trimester dependency correctly: Embryo (hCG) -> Ovary (Corpus Luteum) -> Uterus (Progesterone).
The trap in Option D exploits the misconception that the placenta secretes sufficient progesterone from day 1 of implantation, bypassing the critical role of the corpus luteum.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Placental Endocrine Profile |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |