Biology

Biology

Health
1. Diet
  1. Balance
    1. Protein
    2. Fats
    3. Carbohydrates
2. Excercise
  1. Metabolic rate
    1. Speed at which you use energy
      1. Affected by gender
      2. Affected by weight
      3. Affected by age
      4. Affected by genetics
3. illness
  1. Bacteria
    1. Antibiotics
      1. Kill/prevent growth of bacteria
        Alexander Flemming discovered penicillin in 1928
        Penicillin
        Breaks down cell walls
        eryothromicin
        Stops protein synthesis
        ciprofolxacin
        Prevents DNA replication
        MRSA
        Uh-oh
        Some bacteria grow RESISTANT
        Antibiotics kill weak bacteria, strong ones live on and reproduce
        Population increases
        Avoid unnecessary use of antibiotics
        ALWAYS finish course
    2. Infections
      1. Food poisoning
      2. Cholera
      3. Whooping cough
      4. Typhoid
    3. Bacteria can be grown in labs
      1. In petri dishes
      2. Grown in nutrient agar Jelly
  2. Viruses
    1. Reproduce inside cells, Burst cells, take over other cells
    2. Influenza
    3. Colds/Flus
    4. Measles, Mumps and Rubella
    5. Chicken Pox
    6. Aids
  3. Immunity
    1. Vaccinations
      1. Involves putting small amount of inactive pathogen into body
        Pathogens may be treated, dead, or just such a tiny amount it is harmless
        Inactive pathogen acts as antigen
        Body is stimulated to create antibodies
        If body is later affected by similar pathogen, specific antibodies ready made
        Speeds up killing of pathogens
        If people are vaccinated, they are immunised
        Prevents spreading of disease
    2. Defence
      1. White Blood Cells
        Ingest pathogens
        Produce antibodies specific to pathogen
        Produce antitoxins to counteract toxins from pathrogens
      2. Antibodies
        Pathogens produce antigens- chemicals foreign to body
        Lymphocites produce antibodies
        Antibodies bind to pathogens and destroy them
        Antibodies coat pathogens to make them ingestible by Phagocytes
        Phagocytes and Lymphocytes are white blood cells
        Antigens stimulate body to create antibodies
      3. Hygeine
        Ignaz semelweiss
        Discovers importance of washing hands in hopsitals
Hormones and nervous system
1. Nerves
  1. Receptors
    1. Detect stimuli
    2. Sensitive to chnages in environment
  2. Central Nervous System
    1. Brain and Spine
    2. Receptor is stimulated
      1. Sensory neurones carry signals to CNS
        Relay neurones carry signals around CNS
        Motor neurones carry from CNS to effectors
2. Hormones
  1. Homeostasis
    1. Maintenance of a constant internal environment
    2. In plants
      1. Phototropism
        Positive- grows towards light
        Negatvie - grows away from light
        This is because of gravitropism
        Auxins make things grow longer
        In a plant, auxins are found in the shaded side of the stem
        Shaded side grows longer than lite side
        PLant grows towards light
      2. PLant hormones can be used as weed killers
        They speed up growth
        The weed grows too much and dies
  2. Different parts of body produce hormones for Homeostasis
    1. FSH- causes egg to mature in womb and stimulates oestrogen release
    2. Oestrogen- stops FSH so only one egg per cycle and stimulates LH release
    3. LH gets rid of mature egg from ovary
      1. 'The pill' controls contraceptive hormones
        Increase in oestrogen levels prevents eggs forming
Adaptations
1. Environment
  1. Large area keeps you cool
  2. Large volume keeps you warm
  3. Lichens
    1. Crusty lichens can survive in polluted areas
    2. Bushy lichens need clean air
  4. Water pollution
    1. Can be detected by observing types of animals there
    2. Animals less used to polluted environment wil be found in clean water
2. Food Chains
  1. More Prey= More food= More predators=Less Prey=Less Predators=More Prey
  2. Producers (planst)
    1. Primary Consumers (Sheep)
      1. Secondary consumers (lions)
        predators
        can also be prey
        Energy decreases as you go up the food chain
        used in respiration
        Lost in waste- poo
        Biomass also decreases
        e.g. 1000 caterpillars weigh less than the single tree they feed off
      2. prey
  3. Scavengers- eat already dead
Drugs
1. testing
  1. tested on cells in labs
  2. Tested on animals
  3. Clinical trials
    1. Double blind trials
      1. Use placebo (fake) pills
      2. ensure effect is not psycological
2. Thalidomide
  1. Morning sickness pill
  2. caused birth defects
  3. now used for leprosy
Evolution
1. Darwin's 'opposition' was Lamark

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	Created by Alfie Ross over 11 years ago