Which statement is not correct:-
(a) In the absence of fertilization, the corpus luteum degenerate
(b) During pregnancy all events of menstrual cycle stop
(c) The secretion of LH and FSH deceases gradually during the follicular phase
(d) The menstrual flow result due to breakdown of endometrial lining

Options

A. In the absence of fertilation, the corpus luteum degenerate
B. During pregenency all events of menstrual cycle stop
C. The secreation of LH and FSH deceases gradually during the follicular phase
D. The menstrual flow result due to breakdown of endometrial lining

Answer

To determine which statement is not correct, let's analyze each option step by step:

1. **Statement (a)**: "In the absence of fertilization, the corpus luteum degenerates."
- The corpus luteum is formed after ovulation and plays a crucial role in producing hormones, particularly progesterone, to maintain the uterine lining for a potential pregnancy. If fertilization does not occur, the corpus luteum will degenerate, leading to a decrease in hormone levels and the onset of menstruation.
- **Conclusion**: This statement is correct.

2. **Statement (b)**: "During pregnancy, all events of the menstrual cycle stop."
- During pregnancy, the hormonal changes prevent the menstrual cycle from continuing. The body maintains the corpus luteum initially, which produces hormones to support the pregnancy, and thus, menstruation does not occur.
- **Conclusion**: This statement is correct.

3. **Statement (c)**: "The secretion of LH and FSH decreases gradually during the follicular phase."
- The follicular phase is characterized by the growth of follicles in the ovaries, and during this phase, the levels of Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) actually increase towards the end of the phase, leading to ovulation. They do not decrease during this phase; instead, they rise.
- **Conclusion**: This statement is incorrect.

4. **Statement (d)**: "The menstrual flow results due to the breakdown of the endometrial lining."
- The menstrual flow is indeed caused by the shedding of the endometrial lining when pregnancy does not occur. This breakdown is a key part of the menstrual cycle.
- **Conclusion**: This statement is correct.

**Final Answer**: The statement that is not correct is (c): "The secretion of LH and FSH decreases gradually during the follicular phase."

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