Menstrual cycle Grade 12 Life Sciences Notes with Activities Questions and Answers

On this page you will find Menstrual cycle Grade 12 Life Sciences Notes under Human Reproduction, which includes revision activities with questions and answers to help grade 12 learners to prepare for their tests and exams.

Notes

Day 1–7

• Ovaries: New follicles develop and secrete oestrogen
• Uterus: Lining breaks down and is released (menstruation)

Day 8–13

Ovaries: Mature Graafian follicle develops:

• The Graafian follicle moves to edge of the ovary
• It secretes oestrogen

Uterus: Oestrogen stimulates the endometrium to become thicker and develop more blood vessels and glands

Day 14

Ovaries: Graafian follicle bursts to release an egg cell. The process is called ovulation

Day 15–22

• Ovaries: The Graafian follicle becomes a corpus luteum that secretes progesterone
• Uterus: Progesterone stimulates the endometrium to become even thicker and to develop more blood vessels and glands, ready to receive the embryo if an egg cell is fertilised

Day 23–28

Ovaries: If fertilisation does not take place:

• The corpus luteum shrinks and stops secreting progesterone

If fertilisation takes place:

• The corpus luteum remains active in the ovary and continues to secrete progesterone
• No more follicles develop in the ovaries
• No menstruation takes place

PDF Downloadable Notes on Menstrual cycle:

Question and Answers Activities:

Find short and long questions for Grade 12 Life Sciences, which will help you to prepare for the exams, tests, practical tasks, and assignments.

Questions

1. Name the hormones A and B.
2. Give reasons for your answers in question 1.
3. What event occurs on day 14?
4. Name the other two hormones involved in this cycle.
5. Did fertilisation occur during the cycle shown in Figure 4.6?
6. Explain your answer in question 5.

Answers

Answers to activity 3

1. A – Oestrogen B – Progesterone
2. A: The Graafian follicle secretes oestrogen /Oestrogen reaches
   1. its maximum level before ovulation.
   2. B: The corpus luteum produces progesterone /Progesterone reaches its maximum level after ovulation.

3. Ovulation
4. LH and FSH
5. No
6. Progesterone levels decrease, towards the end of the cycle.

More Resources

Life Sciences: Human Reproduction- The Menstrual Cycle

https://byjus.com/biology/menstrual-cycle/