Reproduction

Reproduction

Fertilisation
1. Def: Fusing of male (sperm) and female (ovum) nucleus
2. Internal e.g. humans, birds, reptiles
3. External e.g. fish
4. Human fertilisation
  1. Egg and sperm fuse
  2. Cell division
  3. Ball of cells
  4. Embryo
  5. Implantation (embryo implants into uterus lining)
  6. Foetus (9-10 weeks) has limbs and looks like human
Puberty
1. Male
  1. Testes produce sperm
  2. muscles develop
  3. Penis grows
  4. Voice breaks
  5. Growth spurt
  6. Hair
    1. Pubic
    2. Facial
    3. Underarm
  7. Stronger smell
2. Female
  1. Growth spurt
  2. Stronger smell
  3. Ovaries produce eggs
  4. Breasts develop
  5. Hips widen
  6. Hair
    1. Underarm
    2. Pubic
Gametes
1. Sperm cell (male)
  1. Tail, streamlined shape
  2. Pointed head
  3. Chemicals
  4. Structures in cytoplasm for energy to swim
  5. Nucleus (half genetic information)
  6. Produced in testes (lower temperature)
  7. Adapted for fertilisation
  8. Released in sugary liquid (semen) , energy for respiration/swim
2. Egg cell/Ovum (female)
  1. Food reserves in cytoplasm
  2. Nucleus (half genetic information)
  3. Jelly covering
  4. Released from ovaries every 28 days in mature females
Contraception
1. Pill
2. Condom
Reproductive organs
1. Male
  1. Testes (produce sperm)
  2. Sperm duct (Carries sperm form testes to urethra)
  3. Urethra
  4. Penis (enters female)
2. Female
  1. Ovaries produces eggs, released every 28 days)
  2. Fallopean tubes/ oviducts (carries egg from ovary to uterus)
  3. Uterus/ womb (baby develops)
  4. Cervix (neck of uterus, sperm deposited here
  5. Vagina (muscular tube where penis enters)
Menstrual Cycle
1. Monthly changes that occur in female reproductive system every 28 days
2. Why? To prepare uterus lining for fertilised eggs
3. Day 1-5. Lining shed i.e.period
4. Repair of uterus wall. Lining thickens
5. Day 14. Ovulation/egg release
6. Lining stays thick, waiting for fertilised egg
7. If no fertilised egg, cycle restarts
8. If fertilised egg, implants into uterus lining
Development of Foetus
1. umbilical cord
  1. Carries food, oxygen, water from mother to baby
  2. Carries CO2 and waste from foetus to mother
  3. Acts as barrier to harmful substances but some pass through e.g. drugs, alcohol, tobacco and viruses
  4. 2 bloods do not mix
2. Amnion
  1. Amniotic fluid
    1. Protects and supports foetus
  2. Amniotic membrane
    1. Breaks at birth
3. Placenta
  1. Substances exchanged between mothers and foetal blood

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	Criado por sulemanadam99 mais de 11 anos atrás