Question 1: Define the term 'menstrual cycle'.

Answer: The series of physiological changes in the female reproductive system that occur approximately every month, involving ovulation, thickening of the uterine lining, and menstruation.

Question 2: Describe the role of hormones in regulating the menstrual cycle.

Answer: Hormones like FSH, LH, oestrogen, and progesterone control the development of follicles, ovulation, and the thickening and shedding of the uterine lining.

Question 3: Explain what happens during ovulation.

Answer: Ovulation is the release of a mature egg from the ovary, typically around day 14 of the cycle, triggered by a surge in luteinising hormone (LH).

Question 1: If a woman’s menstrual cycle lasts 28 days, on which day is ovulation most likely to occur?

Answer: Day 14

Question 2: Calculate the duration of the luteal phase if ovulation occurs on day 14 and menstruation starts on day 28.

Answer: 14 days

Question 3: A woman notices her period starts on day 1 and ends on day 5. If her cycle is regular at 30 days, estimate the likely day of ovulation.

Answer: Day 16

Question 1: Describe a simple experiment to investigate how hormonal levels change during the menstrual cycle. Include the variables involved and safety precautions.

Answer: An experiment could involve collecting blood samples from volunteers at different cycle days to measure hormone levels using assays. The independent variable is the day of the cycle; the dependent variables are hormone concentrations. Control variables include age and health status. Safety precautions include obtaining informed consent, using sterile techniques, and handling blood samples carefully to prevent contamination and infection.

Question 2: Identify two variables that could affect the results of hormonal measurements in the experiment and suggest ways to control them.

Answer: Variables such as the time of day when samples are collected and the individual’s stress levels can affect hormone levels. To control these, collect samples at the same time each day and advise participants to avoid stressful activities before sampling.

Question 1: A woman reports that her menstrual cycle varies between 26 and 32 days. Discuss what this variation might indicate about her hormonal regulation and any potential concerns.

Answer: Variation in cycle length suggests fluctuations in hormonal levels, which could be normal or indicate underlying issues such as hormonal imbalance, stress, or health conditions. If irregular or accompanied by other symptoms, she should consult a healthcare professional for further assessment.

Question 1: Describe how the hormonal changes during the menstrual cycle regulate ovulation and the preparation of the uterus for possible pregnancy. Your answer should include the roles of FSH, LH, oestrogen, and progesterone. (6 marks)

Answer: During the early phase of the cycle, FSH stimulates the development of ovarian follicles, which produce oestrogen. Rising oestrogen levels lead to the thickening of the uterine lining and trigger a surge in LH, causing ovulation. After ovulation, the corpus luteum forms and secretes progesterone, which maintains the uterine lining. If fertilisation does not occur, hormone levels fall, leading to menstruation and the start of a new cycle.

Question 1: Explain how understanding the menstrual cycle is important in the design of hormonal contraceptives.

Answer: Hormonal contraceptives work by regulating or suppressing hormonal signals that trigger ovulation, thereby preventing pregnancy. Knowledge of the cycle helps in designing pills that maintain hormone levels to inhibit ovulation and alter the uterine environment.

Question 2: Discuss how recent advances in biotechnology could improve fertility treatments related to the menstrual cycle.

Answer: Biotechnology can enable precise monitoring of hormonal fluctuations, development of personalised hormone therapies, and improved in-vitro fertilisation techniques by manipulating the menstrual cycle phases. Advances such as hormone assays, genetic screening, and stem cell research may further enhance fertility treatments.