Hormones in Human Reproduction

1. 1 State [2 marks]

   State the roles of oestrogen and progesterone in the menstrual cycle.

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   Model answer

   Oestrogen and progesterone are both involved in maintaining the lining of the uterus.

   Mark scheme

   • Oestrogen is involved in maintaining the lining — 1 mark
   • Progesterone is involved in maintaining the lining — 1 mark
2. 2 Name [3 marks]

   Figure 1 shows the levels of four hormones during the menstrual cycle. Name the hormones shown by the curves A, B and C.

   

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   Model answer

   A is FSH. B is LH. C is progesterone.

   Mark scheme

   • A: FSH — 1 mark
   • B: LH — 1 mark
   • C: progesterone — 1 mark
3. 3 Describe [3 marks]

   Describe what happens to the lining of the uterus during the menstrual cycle.

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   Model answer

   The lining breaks down on days 1 to 5, which is the period. It repairs and thickens between day 5 and day 14. It is maintained from day 14 to day 28 unless the woman becomes pregnant.

   Mark scheme

   • Breaks down in days 1 to 5 — 1 mark
   • Repairs and thickens to day 14 — 1 mark
   • Maintained until day 28 — 1 mark
4. 4 Explain [2 marks]

   The level of LH peaks on day 14. Explain what the peak causes.

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   Model answer

   The surge of LH causes ovulation, which is the release of a mature egg from the ovary.

   Mark scheme

   • Causes ovulation — 1 mark
   • The release of a mature egg from the ovary — 1 mark
5. 5 Explain [3 marks]

   Explain why the lining of the uterus breaks down at the end of the cycle if the woman is not pregnant.

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   Model answer

   After ovulation progesterone maintains the lining. If there is no pregnancy, the progesterone level falls. The lining is no longer maintained, so it breaks down.

   Mark scheme

   • Progesterone maintains the lining — 1 mark
   • If there is no pregnancy the progesterone level falls — 1 mark
   • The lining breaks down — 1 mark
6. 6 Explain [4 marks]

   Explain how FSH, oestrogen and LH interact to cause ovulation.

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   Model answer

   FSH makes an egg mature and stimulates the ovary to release oestrogen. The oestrogen level rises and stops the release of more FSH, so only one egg matures. A high oestrogen level also stimulates the pituitary gland to release a surge of LH. The LH causes ovulation.

   Mark scheme

   • FSH matures the egg and stimulates oestrogen — 1 mark
   • Oestrogen stops further FSH release — 1 mark
   • High oestrogen stimulates the LH surge — 1 mark
   • LH causes ovulation — 1 mark
7. 7 Explain [3 marks]

   Explain the part played by progesterone after ovulation.

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   Model answer

   Progesterone is released by the empty follicle after ovulation. It maintains the lining of the uterus, ready for an embryo. It also stops the pituitary releasing FSH and LH, so no other eggs mature.

   Mark scheme

   • Released after ovulation — 1 mark
   • Maintains the lining — 1 mark
   • Stops FSH and LH release so no new egg matures — 1 mark
8. 8 State [3 marks]

   State the roles of FSH, LH and testosterone in human reproduction.

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   Model answer

   FSH causes an egg to mature in the ovary. LH stimulates the release of the egg. Testosterone is the main male reproductive hormone, which stimulates sperm production.

   Mark scheme

   • FSH causes the maturation of an egg — 1 mark
   • LH stimulates the release of the egg — 1 mark
   • Testosterone stimulates sperm production — 1 mark
9. 9 Describe [2 marks]

   Describe two changes that reproductive hormones cause in a person at puberty.

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   Model answer

   Any two of: eggs begin to mature and are released about every 28 days (females), sperm production starts (males), the secondary sex characteristics develop, such as breasts or facial hair.

   Mark scheme

   • Change 1 — 1 mark
   • Change 2 — 1 mark

Quick check

1. 1

   Which hormone causes ovulation?

   1. AFSH
   2. BLH
   3. COestrogen
   4. DTestosterone
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   B: LH

   A surge of LH causes ovulation.

2. 2

   Which hormone makes an egg mature in an ovary?

   1. AFSH
   2. BLH
   3. CProgesterone
   4. DTestosterone
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   A: FSH

   FSH makes an egg mature in a follicle.

3. 3

   Which hormone maintains the lining of the uterus after ovulation?

   1. AFSH
   2. BLH
   3. COestrogen
   4. DProgesterone
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   D: Progesterone

   Progesterone maintains the lining.

4. 4

   On which day of a 28-day cycle does ovulation usually happen?

   1. ADay 1
   2. BDay 7
   3. CDay 14
   4. DDay 28
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   C: Day 14

   Ovulation usually happens on about day 14.

5. 5

   Which gland releases FSH and LH?

   1. AThe ovary
   2. BThe pituitary gland
   3. CThe thyroid gland
   4. DThe pancreas
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   B: The pituitary gland

   The pituitary gland releases FSH and LH.

6. 6

   Which hormone is released by the testes?

   1. ATestosterone
   2. BOestrogen
   3. CProgesterone
   4. DLH
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   A: Testosterone

   The testes release testosterone.

7. 7

   What does a rise in oestrogen do to FSH?

   1. AIt increases FSH
   2. BIt has no effect
   3. CIt stops further FSH release
   4. DIt turns FSH into LH
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   C: It stops further FSH release

   A rising oestrogen level stops the pituitary releasing more FSH.

8. 8

   What causes the lining of the uterus to break down at the end of a cycle?

   1. AA rise in progesterone
   2. BA rise in oestrogen
   3. CA surge of LH
   4. DA fall in progesterone
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   D: A fall in progesterone

   The level of progesterone falls, so the lining is no longer maintained.