Unit 2-The Biology Of Controlling Fertility

Question 1

When are males fertile and why?

Answer 1

Males are constantly fertile due to a constant level of pituitary hormones.

Question 2

When are females fertile and why?

Answer 2

Female fertility is cyclical.

Fertile period being 1-2 days following ovulation.

Question 3

What can be used to measure a female’s fertile period?

Answer 3

The time of ovulation can be estimated by the number of days after menstruation, a slight rise in body temperature on the day of ovulation and the viscosity of the cervical mucus.

Hormone levels can also be indicators.

Question 4

How can a woman be infertile due to hormones?

Answer 4

A woman be infertile due to not producing enough of the hormones FSH (folllicle stimulating hormone) or LH (luteinising hormone)

Question 5

How can infertility due to lack of hormones be treated?

Answer 5

Ovulation can be successfully stimulated by drugs that contain hormones that can:

• Replicate/mimic FSH and LH.
• Stop the negative feedback of oestrogen into not producing FSH.

Question 6

What can artificially stimulating ovulation lead to?

Answer 6

Super ovulation resulting in multiple births or the production of many eggs for use in ovulation.

Question 7

What is artificial insemination?

Answer 7

Artificial insemination is the insertion of semen into the female reproductive tract by some means other than sexual intercourse.

Question 8

When can artificial insemination be a useful treatment?

Answer 8

Low sperm count.

Condition (for example a virus) means that a couple needs help to conceive.

Donor’s sperm is being used.

Question 9

What is the process of artificial insemination?

Answer 9

Several samples of the man’s sperm can be collected over a period of time and frozen until needed.

They are then defrosted and released into his partner’s reproductive tract at the time when she is likely to be most fertile.

Question 10

How can artificial insemination be used if a man is completely infertile?

Answer 10

Sperm donor can be used with the same process.

Question 11

What does ICSI stand for?

Answer 11

Intra-cytoplasmic sperm injection.

Question 12

What can ICSI be used to treat?

Answer 12

Defective mature sperm.

Very low in number.

Question 13

What does ICSI involve?

Answer 13

The head of a sperm doing drawn up into a very fine needle and injecting it directly into an egg to bring about fertilisation.

Question 14

What does IVF stand for?

Answer 14

In vitro fertilisation

Question 15

What fertility issues is IVF used for?

Answer 15

Poor quality of a man’s sperm.

Woman has blocked oviducts.

Risk of a serious genetic condition.

Donor sperm or donor eggs being used.

Question 16

What does ‘in vitro’ mean?

Answer 16

‘outside of the body’.

Question 17

What are the steps involved in IVF?

Answer 17

1) Hormone stimulation
2) Eggs are surgically removed.
3) The removed eggs are mixed with sperm in a culture dish to allow fertilisation to occur.
4) the fertilised eggs are incubated until they develop into embryos
5) Once each embryo is composed of at least 8 cells, 2 or 3 are chosen to be inserted into the mother’s uterus where they will hopefully implant.
6) The remaining embryos can be frozen in case another attempt is needed.

Question 18

What happens during pre-implantation genetic diagnosis (PGD)?

Answer 18

Used in conjunction with IVF to identify single-gene disorders and chromosomal abnormalities.

Question 19

In what way is fertility in men different from fertility in women?

Answer 19

Men are constantly fertile whereas women are cyclically fertile.

Question 20

What does the oral contraceptive pill/ combined pill contain and what does it do to prevent pregnancy?

Answer 20

The oral contraceptive/combined pill is a chemical method of contraception. It contains synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH.

Question 21

What does the progesterone only/mini pill do to prevent pregnancy?

Answer 21

The progesterone-only (mini) pill causes thickening of the cervical mucus.

Question 22

What does the morning-after/emergency contraceptive pill do to prevent pregnancy?

Answer 22

The morning-after/ emergency pill prevents ovulation or implantation.