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3 Progestrone is a hormone involved in the control of the menstrual cycle - Edexcel - GCSE Biology - Question 3 - 2016 - Paper 1
Question 3
3 Progestrone is a hormone involved in the control of the menstrual cycle. The graph shows the level of progesterone in the blood of three women, labelled X, Y and Z... show full transcript
Worked Solution & Example Answer:3 Progestrone is a hormone involved in the control of the menstrual cycle - Edexcel - GCSE Biology - Question 3 - 2016 - Paper 1
Step 1
Step 2
Suggest a reason for the increasing progesterone level of person X.
Answer
The increasing progesterone level of person X may suggest that fertilisation has occurred. After fertilisation, the hormone is secreted to maintain the uterine lining, which is essential for supporting the developing embryo.
Step 3
Explain the role of progesterone in the menstrual cycle.
Answer
Progesterone plays several critical roles in the menstrual cycle:
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Maintains and thickens the uterine lining: Progesterone is responsible for preparing the endometrium for potential implantation of a fertilized egg. It increases the thickness of the lining, making it more hospitable.
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Inhibits FSH: High levels of progesterone inhibit the secretion of Follicle Stimulating Hormone (FSH) from the pituitary gland. This action helps prevent the maturation of additional follicles during the luteal phase.
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Inhibits LH: Progesterone also inhibits Luteinizing Hormone (LH), which is crucial for the regulation of ovulation. It maintains the hormone levels to stabilize the cycle.
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Triggers menstruation: If pregnancy does not occur, low progesterone levels will trigger the onset of menstruation, leading to the shedding of the uterine lining.