6.6 Reproduction

Question 1

List 4 hormones in the menstrual cycle

Answer 1

FSH, Oestrogen, LH, Progesterone

Question 2

State the source of FSH (follicle stimulating hormone)

Answer 2

Pituitary gland

Question 3

Outline the function of FSH in the menstrual cycle

Answer 3

Stimulates follicular growth; stimulates oestrogen secretion (from developing follicles)

Question 4

State the source of oestrogen

Answer 4

Developing follicles in the ovaries

Question 5

Outline the function of oestrogen in the menstrual cycle

Answer 5

Development of endometrium; stimulates LH secretion (follicular phase); high levels inhibit LH and FSH (luteal phase)

Question 6

State the source of LH (luteinising hormone)

Answer 6

Pituitary gland

Question 7

Outline the function of LH in the menstrual cycle

Answer 7

Surge causes ovulation; development of corpus luteum; stimulates progesterone secretion

Question 8

State the source of progesterone

Answer 8

Corpus luteum in the ovaries

Question 9

Outline the function of progesterone in the menstrual cycle

Answer 9

Thickening of endometrium; high levels inhibit FHS and LH (luteal phase)

Question 10

List three roles of testosterone in males

Answer 10

• Pre-natal development of male genitalia
  
  • Development of secondary sexual characteristics
  • Maintenance of sex drive

Question 11

Outline the process of in vitro fertilisation (IVF)

Answer 11

1. Various drugs injected to stop the menstrual cycle.
   
   2. Large doses of FSH injected to stimulate ovaries to develop many follicles.
   3. HCG hormone injected causing the follicles to mature
   4. Eggs removed from the ovaries and incubated at 37C
   5. Sperm collected and screened
   6. The healthiest sperm are selected and mixed with the eggs in a dish forcing fertilization.
   7. Up to four embryos are selected and implanted in the uterus.
   8. After a few weeks, a pregnancy test is administered.
   9. Done in cases of low sperm count female infertility

Question 12

List two reasons for IVF

Answer 12

• Infertility

* Low sperm count

Question 13

List 2 advantages of IVF

Answer 13

• Chance for infertile couples to have children

* Genetic screening of embryos could reduce suffering from genetic disease

Question 14

List 4 disadvantages of IVF

Answer 14

• Inherited, genetic forms of infertility could be passed onto children, going against natural selection
  
  • Spare embryos are killed or donated to stem cell research
  • Success rate is low ~15% and therefore stressful for couples
  • Could lead to eugenics