human reproduction

• how does sexual reproduction form

  two gametes nuclei fuse together to form a diploid zygote which then divided by mitosis to produce an embryo
• what is a gamete

  a haploid sex cell containing one set of chromosomes
• what is fertilisation

  when two haploid gamete fuse together to form a diploid zygote
• what is an embryo

  the resultant organism when a zygote undergoes repeated cell divisions by mitosis
• how is a sperm cell a specialised cell

  • has a tail which allows it to swim fast towards the egg
  • has many mitochondria for more respiration, more energy for more tail movement
  • has digestive enzymes to allow it to digest through the outer layer of the egg
• how is an ova cell specialised

  • has a large cytoplasm with a food store for the development of a zygote
  • has a jelly coating which only allows one sperm through
  • has haploid nucleuses so it can fuse with another gamete to form a zygote
• what is FSH and where is it produced

  • produced in the pituitary glands
  • causes to egg to mature in the ovary in a structure called a follicle
  • it stimulates the ovaries to produce oestrogen
• what is oestrogen and where is it produced

  • produced in the ovaries
  • it inhibits of the production of FSH
  • It causes the lining of the uterus to grow and thicken
  • it stimulates the release of LH
• what is LH and where is it produced

  • produced in the pituitary gland
  • it stimulates the release of an egg at day 14, ovulation
• what is progesterone and where is it produced

  • produced in the ovaries after ovulation
  • it maintains the lining of the uterus during the second half of the cycle
  • it inhibits the release of FSH and LH
  • when the lining falls towards the end of the cycle, the lining breaks down and passes out through the vagina resulting in a period
• what happens when fertilisation occurs

  • the zygote develops into an embryo and implants in the uterus lining
• what is the function of the placenta

  • it allows the exchange of food such as glucose and oxygen from the mothers blood to the foetus's
  • It allows waste to be deposited like urea from the foetus's blood to the mother say diffusion
• what is the function of the amnion membrane

  • contains amniotic fluid
• what is the function of the amniotic fluid

  it protects the embryo from physical damage by absorbing impacts
• what hormone is produced for girls during puberty

  oestrogen
• what hormone is produced for males during puberty

  testosterone
• what does testosterone cause

  • sperm production
  • growth of pubic / facial hair
  • increase in body mass
• what does oestrogen cause

  • start of the menstruation
  • hips widen
  • growth of breasts