reproduction

• what is the function of the sperm tube?

  Carries sperm from testes to urethra
• what is the function of the prostate gland?

  secretes fluid that nourishes and protects sperm
• what is the function of the urethra?

  tube through which sperm and urine leave the body
• what is the function of the penis?

  releases sperm into vagina in sexual intercourse
• what is the function of the scrotum?

  keep the testes at the best temperature for sperm production outside of the body
• what is the function of the ovaries?

  produce eggs and hormones
• what is the function of the oviducts?

  tubes through which ova travel from the ovaries. this is where fertilisation occurs
• what is the function of the cervix?

  The opening to the uterus which widens during childbirth
• what is the function of the uterus?

  nourishes and protects the developing embryo and foetus throughout pregnancy until birth
• what is the function of the vagina?

  where sperm is released during sexual intercourse
• what are the male gamete?

  sperm cells
• where are sperm cells produced?

  testes
• what hormone is produced in the testes?

  testosterone
• adaptations of sperm cells

  A tail (flagellum) - allows it to swim through female reproductive system.

  A haploid nucleus - produced by meosis, containing half the normal number of chromosomes.

  Many mitochondria - release energy to enable sperm to swim
• what is the female gamete?

  ovum
• where are ova produced?

  ovaries
• what hormone is produced in the ovaries?

  oestrogen and progesterone
• what is fertilisation?


  the fusion of the haploid nuclei of a sperm and egg cell
• what happens after fertilisation?

  1. the zygote travels down the oviduct dividing by mitosis to form a ball of cells (embryo).

  2. when the embryo reaches the uterus, implantation occurs. This is when the embryo sinks into the thick uterus wall to receive nourishment.

  3. the placenta, umbilical cord, amnion and amniotic fluid form.

  4. the embryo differentiates to produce a variety of tissues and organs.
• what is ovulation?


  the release of an ovum from an ovary
• what does the placenta do?

  allows substances to diffuse from the mother's blood to the foetus (e.g. oxygen and glucose).

  substances can also diffuse from the foetus to the mother's blood (e.g. urea and carbon dioxide)
• how is the placenta adapted for diffusion?

  1. large surface area between it and the uterus wall

  2. villi which further increase surface area of the placenta

  3. a rich supply of maternal blood vessels

  4. thin membranes for short diffusion distances
• what does the umbilical cord do?

  connects foetus to placenta - contains umbilical artery and vein
• what does the umbilical artery do?

  carries urea and carbon dioxide from the foetus to the mother's blood
• what does the umbilical vein do?

  carries oxygen and nutrients from the mother's blood to the foetus
• what are maternal blood and foetal blood systems separated by?

  thin membranes which allow diffusion to occur
• what is the amnion?

  a membrane which forms around the embryo. inside the amnion is amniotic fluid which surrounds the embryo inside, cushioning and protecting it
• what is puberty?


  a period of development in which large physical and emotional changes take place in an individual
• what are hormones?


  chemical messengers
• what is the sex hormone in males and where is it produced?

  testosterone - produced in testes
• what is the sex hormone in females and where is it produced?

  oestrogen - produced in the ovaries
• what changes occur in males after puberty?

  facial, body and pubic hair grows.

  sexual organs enlarge (e.g. penis).

  voice deepens.

  the body becomes more muscular.

  sexual awareness and drive increases.
• what changes occur in females after puberty?

  pubic and armpit hair grows.

  sexual organs enlarge and breasts develop.

  menstruation begins.

  the pelvis and hips widen.

  sexual awareness and drive increases.
• how long is the menstrual cycle?

  28 days
• what happens on days 1-5 of the menstrual cycle?

  menstruation occurs - the uterus lining breaks down and is released through the vagina.

  oestrogen and progesterone levels are low
• what happens on days 6-13 of the menstrual cycle?

  the uterus lining begins to renew itself in preparation for the release of an egg.

  oestrogen increases causing initial repair of the uterus lining.

  progesterone increases and is important in the buildup of the uterus lining
• what happens on day 14 of the menstrual cycle?

  oestrogen levels peak, this causes ovulation - the release of an egg
• what happens on days 15 - 28 of the menstrual cycle?

  progesterone levels peak after ovulation. progesterone ensures the thickness of the uterus lining is maintained or the placenta and other pregnancy structures form if fertilisation has occured. if pregnancy has not occured the egg passes out of the vagina and the levels of both hormones drop, causing the cycle to begin again.
• functions of oestrogen


  - initial repair of the buildup of the uterus lining

  - stimulation of ovulation
• progesterone function


  responsible for the buildup and maintenance of the uterus lining