Unit 2 Flashcards - Production of gametes, biological control of fertility, screening

Question 1

Name the cells that gametes are produced by?

Answer 1

Germline cells

Question 2

Name the organs that produce sperm.

Answer 2

Testes

Question 3

Name the tissue within the organ that produces sperm.

Answer 3

Seminiferous tubules

Question 4

What hormone does the interstitial cells produce?

Answer 4

Testosterone

Question 5

What does the prostate gland and seminal vesicles secrete?

Answer 5

They secrete fluids that maintain the mobility and viability of the sperm

Question 6

What do the ovaries contain?

Answer 6

Immature Ova in various stages of development

Question 7

What is each ovum surrounded by?

Answer 7

A Graafian follicle that protects the ovum and secretes hormone.

Question 8

Where does fertilisation take place?

Answer 8

The Oviduct

Question 9

What is a zygote?

Answer 9

A fertilised egg

Question 10

What hormone is released to begin puberty?

Answer 10

Releaser hormone

Question 11

Name the organ which releases releaser hormone.

Answer 11

Hypothalamus

Question 12

What does releaser hormone stimulate?

Answer 12

The pituitary gland to release FSH and ICSH in males and FSH and LH in females

Question 13

What does FSH in males stimulate?

Answer 13

Sperm Production in the seminiferous tubules and activate the prostate gland and seminal vesicles

Question 14

What does ICSH stimulate in males?

Answer 14

The interstitial cells to produce testosterone

Question 15

What do high levels of testosterone cause?

Answer 15

The inhibition of the pituitary gland which prevents the release of FSH of ICSH
This is negative feedback and brings the testosterone levels back to set point
Sperm production decreases until a low level is detected. At that point, the pituitary gland begins to release FSH and ICSH again.

Question 16

How long does an average menstrual cycle take?

Answer 16

28 days

Question 17

What day is regarded as the first day of the menstrual cycle?

Answer 17

Day one. This is the first day of a girls period.

Question 18

What is the function of FSH in females?

Answer 18

Stimulates the development of the Graafian follicle and production of oestrogen by the follicle and ovarian tissue.

Question 19

What is the function of oestrogen?

Answer 19

Stimulates the proliferation of the endometrium preparing it for implantation and affects the consistency of cervical mucus making it more easily penetrated by sperm.

Question 20

What do peak levels of oestrogen stimulate?

Answer 20

A surge in secretion of LH

Question 21

What does LH stimulate?

Answer 21

Ovulation

Question 22

What day does ovulation typically occur on?

Answer 22

Day 14

Question 23

What is day 1-13 typically referred to as?

Answer 23

The folicular phase

Question 24

What is day 15-28 typically referred to as?

Answer 24

The luteal phase

Question 25

After ovulation, what does the graafian follicle develop into?

Answer 25

Corpus Luteum

Question 26

What causes the graffian follicle to develop into this structure?

Answer 26

LH

Question 27

Which hormone does the corpus luteum secrete?

Answer 27

Progesterone

Question 28

What is the function of progesterone?

Answer 28

To thicken the endometrium and cause vascularisation of the endometrium, preparing it to receive a blastocyst if fertilisation occurs.

Question 29

What does high concentrations of progesterone cause?

Answer 29

The inhibition of the pituitary gland from secreting FSH and LH, which prevents further follicles from developing.

Question 30

What does the the lack of LH cause?

Answer 30

The degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation.

Question 31

Is female fertility cyclical or continuous?

Answer 31

Cyclical. Females are only fertile for 2-3 per month. Males are continually fertile.

Question 32

How can female infertility be treated?

Answer 32

Ovulatory drugs mimic the action of FSH and LH. These drugs can cause super ovulation that can result in multiple births or be used to collect ova for in vitro fertilisation (IVF) programmes.
Stimulating ovulation. Ovulation stimulated by drugs that prevent the negative feedback effect of oestrogen on FSH secretion.

Question 33

Name two processes which females can fall pregnant without having sexual intercourse

Answer 33

Artificial insemination or IVF

Question 34

What does artificial insemination involve?

Answer 34

Collecting samples of the male’s sperm over time (preserved by freezing) and depositing them in the female reproductive system (artificially). The act of sexual intercourse does not take place.

Question 35

Under what circumstance can artificial insemination be used?

Answer 35

If male’s have a low sperm count. If a man is sterile, a donor who has a normal sperm count can be used.

Question 36

Describe intra-cytoplasmic sperm injection (ICSI)

Answer 36

If mature sperm are defective or very low in number ICSI can be used
The head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation.

Question 37

Describe the process of IVF

Answer 37

1. The female is given hormonal treatment to stimulate multiple ovulation
2. Eggs are removed from her ovary
3. The eggs and sperm are mixed in a culture dish of nutrient medium to allow fertilisation to occur.
4. The eggs are incubated in the medium for 2-3 days to allow cell division to occur and form embryos of 8 or more cells
5. Two or three embryos are chosen and then inserted via the vagina into the mothers uterus.
6. The remaining embryos are frozen and stored in case a second attempt at implantation is required.

Question 38

Before the embryos are inserted in the vagina of the female, what can be removed?

Answer 38

Cells to be be tested for genetic abnormalities.