The graph shows the concentration of four hormones during the menstrual cycle.
Which line represents progesterone?
▶️ Answer/Explanation
Ans: B
Progesterone exhibits a distinct pattern during the menstrual cycle:
- It rises sharply after ovulation (around day 14) as the corpus luteum forms.
- Remains elevated throughout the luteal phase (days 15-28) to maintain the uterine lining.
- Declines if fertilization doesn’t occur, triggering menstruation.
In the graph, line B matches this pattern perfectly, showing:
- Low levels in the follicular phase (days 1-13)
- Steep rise post-ovulation
- Sustained high levels before dropping at cycle’s end
This hormonal profile confirms B represents progesterone.
The graphs show the concentrations in the blood of four hormones involved in controlling the menstrual cycle. Which line represents FSH (follicle-stimulating hormone)?
▶️ Answer/Explanation
Ans: B
FSH (Follicle-Stimulating Hormone) has two key characteristics in the menstrual cycle: (1) it peaks just before ovulation to stimulate follicle development, and (2) shows a smaller secondary rise in the luteal phase.
In the graph, line B displays this pattern with an initial peak around day 10-14 (follicular phase) and a smaller rise later. The other lines likely represent: estrogen (sharp pre-ovulation peak), progesterone (post-ovulation rise), or LH (mid-cycle surge). Thus, B correctly matches FSH’s behavior.