B1 B2 B3

B1 B2 B3

1. Nucleus contains genetic material

   • Arranged into chromosomes (moles of DNA)
     • Gene short length chromosome // diff. versions of same called ALLELLE
       • Code for making proteins - diff characteristic.
         • STRUCTURAL - skin, hair, blood
         • FUNCTIONAL - digestive enzymes (amalyse)
       • GENOTYPE - genes it has PHENOTYPE - expressed
         • HOMOZYGOUS - Two same allele HETEROZYGOUS - Two diff allele
           • DOMINANT
           • RECESSIVE
     • Sex cells - 23 chromosome // from parents
       • Men - XY Chromsome
         • Testes // Testosterone
       • Women - XX Chromosome
         • Ovaries // Oestrogen

2. Genetic disorders caused by faulty alleles

   • CYSTIC FIBROSIS // Recessive Alleles
     • Respiratory probs // thick sticky mucus // chest infections // difficult digestion
     • 1 in 25 Carriers
     • carrier or sufferer
   • HUNTINGDON'S // Dominant Alleles
     • Tremors // Memory loss // Poor concentration // Mood change
     • 50% chance
     • late onset
   • Genetic Testing - embryo // children // adults
     • Pre-implantation genetic disorder
     • carry alleles for genetic disorders
     • not 100% accurate // misinterpreted or contaminated
     • not 100% safe // cause miscarriage
     • positive // all family tested? // false negative positive
     • terminate pregnancy // financial // coping // right to life
     • discrimination // employers // insurance

3. Clones are genetically identical organisms

   • Asexual
   • Embryo split
   • Artificial

4. Stems Cells - UNSPECIALISED

   • EMBRYONIC - any cell
     • muscle cells // insulin producing // nerves
   • ADULT - maintain repair old damage tissue
     • bone marrow transplant
       • sickle cell anaemia

5. Symptoms are caused by cell damage or toxins

   • Microorganisms reproduce quickly inside body (warm moist conditions)
     • Calculate grown of pop.
       • Number at start
       • how long it takes to reproduce
       • how long left to reproduce
     • Immune system fights off invading microbes
       • white blood cell detect 'foreign' // engulf & digest
         • antibodies specific to antigen
           • mark - other W.B.C
           • bind and neutralise
           • kill directly
           • memory cells stay around
     • Vaccination safe version of microorganism
       • Immunisation - dead / inactive antigens - memory cells
         • Epidemics prevented by vaccination
           • Side effects // Genetic diff - react diff
       • Antimicrobials inhibit of kill bacteria, fungi and viruses
         • M.O evolve - RESISTANT - mutation in DNA
           • Reproduce - gene pass on // more common
         • Drugs tested in lab
           • Human cells
             • Live mammal
               • human volunteer
                 • Healthy - safe
                 • PLACEBO
                 • BLIND TRIAL
                   • DOUBLE BLIND TRIAL
                     • OPEN LABEL TRIAL

6. Heart & blood cells supply blood to body

   • HEART // Right - deoxygenated to lungs // Left - oxygenated to body
     • Blood supplied to heart from coronary arteries from aorta
       • ARTERIES - blood away from heart // high pressure - strong elastic walls
       • VEINS - blood to heart // low pressure - lumen and valves
       • CAPILLARIES - exchange substance in blood // diffusion
       • Pulse rate measure BPM
         • DIASTOLIC - contract // SYSTOLIC - relax
           • H.B.P increase risk of heart disease
             • Fatty deposit restrict blood flow
               • Blood clot form
                 • Coronary blocked no oxygen - heart attack
             • Poor Diet - high cholesterol / salt
             • Smoking - CO reduce O2 // Nicotine increase H.R
             • Stress
             • Drugs & Alcohol

7. HOMEOSTATIS - maintaining constant internal environment

   • Negative feedback counteracts change
     • ADH secreted from pituitary gland
       • Water - too high // less ADH // kidneys reabsorb less // more urine - dilute.
       • Water - too low // more ADH // kidneys reabsorb more // less urine - high conc.
       • Alcohol suppress - dehydration
       • Ecstasy increase

8. A species is a group of organisms that can breed together to produce fertile offspring

   • Adapt to survive
     • Cacti - wax and spines // reduce water loss
     • Fish - gills // streamline // swim bladder
     • Natural selection - "Survival of the Fittest"
       • Competition // passed on
       • Rabbits
       • Selective Breeding - desired features
         • Cows
   • Life on Earth - 3500 million y.a.
     • Evolution - new species
       • Isolated // mutation // natural sel. // enivro
         • Charles Darwin Theory of Evolution
         • Lamarck - chara used lots - more developed
       • Biodiversity
         • Number of species
         • Genetic variation
         • Range of different types
         • KINGDOMS - bacteria, fungi, plant, algae, plants, animals
         • Interdependence - pop. inc / dec.
           • EXTINCTION - enviro. change // competition // disease // food web
         • Energy in Ecosystems
           • Sun - main source // photosynthesis - convert
             • Transfer - consumption // decay - dead n waste
               • Lost - respiration // heat (const. temp) // waste products
                 • efficiency = energy available / energy was available x 100
           • CO2 powers photosynthesis
             • CO2 into glucose
               • eating passes compounds in food chain
                 • Respiration releases CO2
                   • Die n decompose - release CO2 from decomposers respiring
                     • Combustion release CO2

9. Nitrogen need for growth proteins

   • Fixation - N2 into nitrates
     • Lightning
     • Fixing bacteria
     • Decomposer - proteins & urea to ammonia
       • Nitrifying - ammonia into nitrates
         • Denitrifying - nitrate to N2

10. Enviro. Change

    • Temp - Climate
    • Nitrate - Water
    • CO2 - Air
    • Air - Lichen // SO4 - no. - clean
      • Water - Mayfly // O2 - no.- clean
        • Water - Phytoplankton // Algal bloom
    • SUSTAINABILITY - meeting demands of today without harming enviro so future gens. can meet theirs
      • Renewable materials
      • Less energy
      • Less pollution