Reproduction

Question 1

Label a diagram of a sperm cell.

Answer 1

Check notes.

Should contain:

Acrosome (contains enzymes that help the sperm get through the layers of the egg.
Nucleus (contains genetic material, aka haploid)
Mitochondrion
Plasma membrane
Tail

Question 2

What is an ovum?

Answer 2

Egg cell.

Question 3

What are the functions of the reproductive system?

Answer 3

Make sex hormones
Make gamete’s
Bring gametes together
In females provides location for embryo to develop and continue a good source (breast milk)

Question 4

Label a diagram of the male reproductive system

Answer 4

Check notes.
Should contain:
Prostate gland
Urethra
Penis
Scrotum
Testes
Sperm tube

Question 5

Label a diagram of the female reproductive system.

Answer 5

Check notes.
Should contain:
Ovary
Oviducts
Uterus
Cervix
Vagina

Question 6

What are some puberty changes that occur in males and females alike?

Answer 6

Sex hormones circulate
Pubic and under-arm hair
Sex organs get larger
Pituitary gland is active
Sweat glands develop
Growth spurt
Sexual awareness and drive increase

Question 7

What are some puberty changes that happen to females?

Answer 7

Menstrual cycle
Hips widen
Breasts develop
Layers of fat

Question 8

What are some puberty changes that happen to males?

Answer 8

Sperm produced
Voice deepens
Face and body hair
Muscles develop

Question 9

List the stages of the menstrual cycle.

Answer 9

Days 1-5: menturation
Blood flows out of the vagina as the lining of the uterus breaks up.

Days 6-10:
Lining of uterus starts to regrow.

Days 11-17:
Sperm are likely to cause fertilisation

Days 13-15: Ovulation
Egg released from ovary

Days 18-28:
If the egg is not fertilised it dies and eventually passes out of the vagina

Question 10

Where does fertilisation take place?

Answer 10

Oviduct

Question 11

Describe the process of fertilisation

Answer 11

Sperm deposited in vagina during intercourse
Sperm meet egg in oviduct
One sperm (haploid) enters the egg (haploid). Head goes in and tail left outside.
Nucleus of sperm fuses with nucleus of egg, forming a diploid zygote
Zygote cell divides by mitosis and grows into a ball of cells
Travels down the oviduct. After several hours the ball of cells is called an embryo.
Embryo implants in uterus and continues dividing to form specialised organs.

Question 12

Label a diagram of a pregnant uterus.

Answer 12

Check notes.
Should contain:
Oviduct
Foetus
Placenta
Umbilical cord (containing umbilical artery and vain)
Amnion
Amniotic fluid
Uterus wall
Cervix
Vagina

Question 13

List some reasons for infertility,

Answer 13

Failure of ovary to produce eggs
Oviducts may be blocked or twisted
Complications of an STI
The lining of a Uterus does not develop properly to enable implantation to occur
Vagina may be hostile to sperm e.g. too acidic or too thick
Male may not produce enough sperm
Sperm may not be healthy or motile (moving)
Impotence

Question 14

How can fertility drugs help with fertility?

Answer 14

Hormone treatment.

Increases egg production in females. Effective if problem is due to low egg production, but IVF is usually required.

Question 15

How can IVF help with fertility? What is the process?

Answer 15

In Vitro fertilisation.
Women given fertility drugs to produce several eggs.
Eggs collected from ovaries surgically.
Sperm is donated and added to egg in a lab procedure.
Successful embryos replaced in the woman’s uterus (usually 2)

Question 16

What are some controversies about IVF?

Answer 16

Religious objection
Excess embryos being destroyed or stored
Cost
Multiple births.

Question 17

What are some mechanical contraceptives?

Answer 17

Male and female condoms
Act as a barrier to stop sperm passing up the reproductive system.
Advantage: easily obtained and also protects against STIs
Disadvantage: unreliable if not used correctly

Question 18

What are some chemical contraceptives?

Answer 18

Contraceptive pill:
Taken by women, preventing ovaries from releasing eggs by changing hormone levels
Advantage: Very reliable
Disadvantages:
Causes side effects such as weight gain, mood swings, and can increase risk on blood clots.
Women need to remember to take the pill daily for around 21 consecutive days each cycle

Implants:
Small tubes about 4cm long inserted under the skin and slowly release hormones to prevent the development and release of an egg,
Advantages:
Very reliable
Can work for up to 3 years.
Disadvantages:
Do not protect against STIs
Can prevent menstruation taking place

Question 19

What are some surgical contraceptives?

Answer 19

Vasectomy:
Cutting of sperm tubes, preventing sperm from entering the penis
Advantages: virtually 100% reliable
Disadvantages very difficult or impossible to reverse

Female sterilisation:
Cutting of oviducts, preventing ova from moving through the oviduct and being fertilised.
Advantage: ^
Disadvantage: ^