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Question #45379
The Question
During the first trimester of human pregnancy, the maintenance of the endometrium is critical for embryonic survival. Which of the following statements regarding the hormonal regulation during this period is INCORRECT?
Options
- A.
The syncytiotrophoblast secretes human chorionic gonadotropin (hCG), which rescues the corpus luteum from degeneration.
- B.
The maintenance of the corpus luteum and its progesterone secretion is directly dependent on the maternal hypothalamic-pituitary axis.
- C.
High titers of circulating progesterone and estrogens exert negative feedback, suppressing the release of maternal pituitary gonadotropins.
- D.
A sudden drop in progesterone levels or the administration of a progesterone antagonist will lead to decidual sloughing and miscarriage.
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
Syncytiotrophoblast|hCG|Progesterone_Estrogen_Feedback
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the non-pregnant menstrual cycle (where pituitary LH maintains the corpus luteum) with early pregnancy.
They fail to recognize that early pregnancy relies on placental autonomy (hCG), while the maternal H-P axis is actually suppressed by high steroid levels.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Implantation and Syncytiotrophoblast |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |