3a - Reproduction in humans

Question 1

What are special sex organs called?

Answer 1

gonads

Question 2

What is the male gamete?

Answer 2

sperm cell

Question 3

Where are male gametes produced?

Answer 3

testes

Question 4

Where are female gametes produced?

Answer 4

ovaries

Question 5

What is the function of a sperm cell?

Answer 5

to carry the male genetic information and fertilise the female egg

Question 6

How many sperm cells does one ejaculation contain?

Answer 6

339 million

Question 7

Why do sperm cells have a flagellum?

Answer 7

helps the sperm cell swim

Question 8

What does the tip of the head of sperm cells have?

Answer 8

contain enzymes to attack the coat of the egg and several mitochondria to provide energy to swim

Question 9

Why do sperm cells contain cytoplasm?

Answer 9

to give it a streamlined shape

Question 10

What is the function of an egg cell?

Answer 10

to carry the female genetic information and provide nutrients for the embryo following fertilisation

Question 11

Why do egg cells contain cytoplasm?

Answer 11

contains a store of food energy

Question 12

Why do egg cells have a jelly coat?

Answer 12

make sure that only one sperm cell can enter the egg cell

Question 13

Which gamete is larger?

Answer 13

egg cell

Question 14

How many egg cells are produced?

Answer 14

1 a month

Question 15

How many sperm cells are produced?

Answer 15

millions

Question 16

Are egg cells able to move?

Answer 16

no

Question 17

Are sperm cells able to move?

Answer 17

yes

Question 18

Do egg cells have a food source?

Answer 18

yes

Question 19

Do sperm cells have a food source?

Answer 19

no

Question 20

When do boys hit puberty?

Answer 20

13-16

Question 21

When do girls hit puberty?

Answer 21

11-14

Question 22

What is puberty controlled by in males?

Answer 22

testosterone

Question 23

What is puberty controlled by in females?

Answer 23

oestrogen

Question 24

What are some female body developments that hit them during puberty?

Answer 24

• breasts develop
• ovaries start to release eggs (period starts)
• increase in body mass (hips widen)

Question 25

What are some male body developments that hit them during puberty?

Answer 25

- voice breaks (get deeper) - testes and penis develop - sperm is produced by testes - hair grows on face and body - increase in body mass (body becomes more muscular)

Question 26

What are some female and male body developments that hit them during puberty?

Answer 26

- pubic hair grows - underarm hair grows - stronger body smell

Question 27

What does the menstrual cycle consist of?

Answer 27

- involves an egg and making sure the uterus lining is in perfect condition for implantation - if pregnancy does not occur the body will reset

Question 28

The menstrual cycle is controlled by ________

Answer 28

hormones

Question 29

How long does the menstrual cycle last?

Answer 29

28 days

Question 30

What is Phase 1 of the menstrual cycle?

Answer 30

Menstruation - the uterus lining breaks down for 4 days

Question 31

What is Phase 2 of the menstrual cycle?

Answer 31

the uterus lining builds up again for 10 days

Question 32

What is Phase 3 of the menstrual cycle?

Answer 32

Ovulation - by this time a follicle has matured which releases an egg

Question 33

What is Phase 4 of the menstrual cycle?

Answer 33

the wall is maintained for 14 days, if the egg is unfertilised then the lining breaks down and the cycle starts again

Question 34

What does oestrogen cause in the menstrual cycle?

Answer 34

- causes the lining of the uterus to build up | - stimulates another hormone which leads to ovulation

Question 35

What does progesterone cause in the menstrual cycle?

Answer 35

- maintains the lining of the uterus | - inhibits the release of further eggs by stopping other hormones being produced

Question 36

What is the journey of the sperm?

Answer 36

- sperms are produced in the testes - they mix with liquid from glands to form semen - semen is ejaculated into vagina during sexual intercourse - the sperm cells swim through the cervix and into the uterus - they swim up the oviduct (fallopian tube)

Question 37

What is fertilisation?

Answer 37

nuclei of the 2 haploid cells fuse to make a new diploid cell

Question 38

What happens when the egg pushes itself through the cell membrane?

Answer 38

the sperm cell loses its tail

Question 39

What is created from fertilisation?

Answer 39

zygote

Question 40

What is the process called that the zygote undergoes to become an embryo?

Answer 40

mitosis

Question 41

Where does the embryo implant itself?

Answer 41

in the endometrium (in the uterus)

Question 42

What does the embryo develop in the uterus lining?

Answer 42

- placenta | - amniotic sac

Question 43

When does the embryo become a foetus?

Answer 43

when the embryo becomes a recognisable human

Question 44

What does the placenta provide the foetus with?

Answer 44

- oxygen - nutrients to the growing embryo - removes waste (urea, carbon dioxide) - secretes female hormones that maintain pregnancy

Question 45

How is the placenta joined to the foetus?

Answer 45

via the umbilical cord

Question 46

Does the mother's blood mix with the foetus's blood?

Answer 46

no

Question 47

What is the purpose of the amniotic sac?

Answer 47

- encloses the developing embryo | - secretes a fluid called amniotic fluid which protects the developing embryo