Unit 16 - Human Reproduction Flashcards
Label the following diagram of the male reproductive system
State 2 functions of the testes
- They produce hormones
- They produce sperm
State 2 functions of the penis
- Can become firm, to insert into the vagina of the female during sexual intercourse in order to transfer sperm
State 2 functions of the male urethra
- It allows urine to exit the body from the bladder
- It is used during ejaculation to release semen
State the function of the scrotum
A sac that holds the testes outside the body, keeping them cooler than body temperature
State the function of the sperm duct
Muscluar tube that links the testis to the urethra to allow the passage of semen containing sperm
State the function of the prostate gland
It produces prostate fluid which combines with sperm cells to make semen
Label the following diagram of the female reproductive system
State 2 functions of the ovaries
- They produce eggs
- They produce hormones
State 2 functions of the vagina
- To receive the penis during intercourse
- It is used as the birth canal during childbirth
State the function of the oviduct
- Carries an ovum to the uterus, with propulsion provided by tiny cilia in the wall
- It is also the site of fertilisation
State 2 functions of the cervix
- A ring of muscle, seperating the vagina from the uterus
Define fertilisation
The fusion of the nucleus of a male gamete with the nucleus of a female gamete
Compare sperm and egg cells in terms of size
Sperm cells are significantly smaller than egg cells
Compare sperm and egg cells in terms of structure and shape
Sperm cells are long and thin with a head and tail whereas egg cells are large and in the shape of a sphere or ovoid
Compare sperm and egg cells in terms of their ability to move
- Sperm cells have large energy stores and a long tail to help them to move quickly
- Egg cells do not have this and so are relatively non-motile
Compare sperm and egg cells in terms of the number of each cell
There are many more sperm cells than egg cells (up to 100 million sperm per millilitre of ejaculate)
State 2 adaptive features of sperm cells
- Long flagellum
- Contain enzymes
Explain 3 adaptive features of sperm cells
- Lots of mitochondria in the middle section provide energy for movement
- Enzymes in the acrosome break down the outer membrane of the egg
- Long whip-like flagellum used for movement
State 2 adaptive features of egg cells
- Large energy stores
- Jelly-like coat
Explain the 2 adaptive features of egg cells
- Large energy stores allow for lots of cell divisions and growth
- Jelly-like coat ensures that only one sperm can fertilise the egg as it changes after fertilisation
Briefly describe the early development of an embryo
- After fertilisation a zygote is formed
- The zygote implants in the uterus wall and becomes an embryo
What is the function of the umbilical cord?
- It delivers oxygenated blood and nutrients to the developing foetus
- It removes deoxygenated blood and waste products from the developing foetus
What is the function of the placenta?
- To allow the removal of waste gases and excretory products from the foetus
- To act as a barrier for toxins and pathogens
- To provide the foetus with dissolved nutrients
What is the function of the amniotic sac and amniotic fluid?
They help to protect the developing foetus
Describe the growth of the foetus over time
- The foetus begins by developing and becoming more complex
- In the later stages of pregnancy, the foetus increases in size
How can certain toxins and pathogens be harmful to the developing foetus?
The toxins and pathogens can pass across the placenta and can damage the foetus
Name one toxin that can affect a developing foetus
Nicotine found in cigarette smoke
Name one pathogen that can affect a developing foetus
The rubella virus
Describe how women should control their diet during pregnancy
- Avoid smoking or drinking as this can damage the foetus
- Make sure to have a balanced diet with a focus on nutrients like iron for the development of blood and calcium for the development of bones
State one advantage of breastfeeding over bottle feeding using formula milk
Breastfeeding provides the child with important antibodies from the mother which provides protection against disease
State one disadvantage of breastfeeding over bottle feeding using formula milk
Breastfeeding may be painful for the mother
State one advantage of bottle feeding using formula milk over breastfeeding
The mother does not need to control her diet to provide the correct nutrients to her baby
State one disadvantage of bottle feeding using formula milk over breastfeeding
Bottle feeding can be an extra expense for parents
State the 6 main stages of labour and birth
- The amniotic sac breaks (water breaking)
- The muscles in the wall of the uterus contract
- Widening of the cervix opening (dillation)
- Passage of the baby through the vagina
- Tying and cutting the umbilical cord
- Delivery of the afterbirth
What role does testosterone play during puberty?
- Triggers growth and development of the penis and testes
- Causes the voice to deepen
- Triggers the growth of pubic hair
- Increases muscle mass
What role does oestrogen play during puberty?
- Increases breast size
- Triggers the development of the uterus
- It causes eggs to mature during the menstrual cycle
Where is oestrogen secreted from?
The ovaries
Where is progesterone secreted from?
The ovaries
What happens on day 1-4 of the menstrual cycle?
The uterus lining is shed during menstruation
What happens on day 4-14 of the menstrual cycle?
The uterus lining then begins to grow again in preparation to receive an egg
What happens on day 14 of the menstrual cycle?
An egg is released
What happens on day 14-28 of the menstrual cycle?
The lining of the uterus is maintained
What does follicle stimulating hormone (FSH) do?
FSH stimulates the follicle to mature and release oestrogen
What does luteinising hormone (LH) do?
A surge in LH causes the release of an egg from a follicle (ovulation)
What does progesterone do?
Progesterone maintains the womb lining
What hormone does progesterone inhibit?
Progesterone inhibits follicle stimulating hormone (FSH) and Luteinizing hormone (LH)
