Human Reproduction

Question 1

Describe the structure of the male reproductive system

Answer 1

• Two testes where sperm are produced, kept outside of the body, in the scrotum to keep sperm at a lower temperature so that production is good
• Sperm ducts carry sperm from testes to penis, through prostate gland and seminal vesicles, which produce the liquid for the sperm to swim in
• Semen passes along sperm duct to urethra outside the body
• When sexually excited penis fills with blood and causes an erection

Question 2

Describe the female reproductive system

Answer 2

• Two ovaries produce eggs, positioned either side of the uterus and joined to it by oviducts
• Every month until menopause, one ovary releases one egg which tracked down the oviduct to the uterus and if not fertilised then will be flushed from womb in period
• Below the uterus, there is the vagina, an elastic, muscular tube, which leads into the cervix and then the uterus

Question 3

How does testosterone cause secondary sexual characteristics?

Answer 3

At puberty, increased secretion of testosterone from testes causes
- increase in rate of growth
- hair growth on face and body (inc pubic)
- penis, testes and scrotum growth
- deepening of voice
- increased muscle development
- sperm production

Question 4

How does oestrogen cause secondary sexual characteristics?

Answer 4

In females, progesterone and oestrogen are both produced in ovaries and at puberty increased secretion of oestrogen causes
- increase in rate of growth
- breast development
- vagina, oviduct and uterus development
- start of menstrual cycle
- hips widening
- pubic and underarm hair growth

Question 5

What is the purpose of amniotic fluid?

Answer 5

• Protects foetus from damage and reduces the effect of large temperature variations which would affect development

Question 6

What is the purpose of the placenta?

Answer 6

An organ that allows constant exchange of materials between mother and foetus. It develops from fetal tissues and has a large number of blood vessel that are very close together but don’t touch so that blood doesn’t mix. If it did then higher blood pressure could damage the foetus, it also helps to prevent pathogens and chemical from getting into the blood. The foetus is joined by try umbilical cord and dissolved food molecules, oxygen and other nutrients diffuse from mother to foetus and waste products vice versa