errors

• name two components of CNS

  spinal cord + brain
• three properties of a reflex action:

  • automatic
  • protective
  • fast
• a sense organ = a group of receptor cells that respond to specific stimuli
• effect of motor neurone disease on reflex action:

  • slowed down
  • electrical impulses travel slower along motor neurone
• reflex arc:

  A) receptor cells

  B) muscle - effector

  C) sensory neurone

  D) relay neurone

  E) synapse

  F) synapse

  G) motor neurone

  H) spinal cord

  
• stimulus -> receptor -> sensory neurone -> spinal cord -> synapse -> relay neurone -> synapse -> motor neurone -> effector -> response
• name of group of micro-organisms to which pathogen that causes chlamydia belongs?

  bacteria
• how to improve strength of evidence (capture-recapture)

  • increase area sampled
  • survey more than one area
• two precautions to reduce risk of harm to individuals/habitat? (capture-recapture)

  • don't litter
  • don't disturb other wildlife
• brain controls water blood levels
• dehydrated person -> receptor in brain recognises low water blood level -> more ADH released into blood by pituitary gland -> enters kidney and makes collecting duct wall more permeable to water -> more water reabsorbed into blood -> blood water levels return to normal through negative feedback -> urine produced has a small volume + more concentrated
• blood should never pass through kidney and be present in urine
• process of genetic profiling = cutting DNA into short pieces which are then separated into bands of DNA and compared
• genetic engineering = transferring a gene from one organisms DNA into another organism's DNA
• temperature that agar plates have to be incubated at + why?

  36.5 - 37.5 -> encourage growth of cultures without growing pathogens (pathogens grow at human body temp)
• if there are 22 bacteria there will be 22 colonies (one bacterium = one colony)
• function of cornea = allows light in to eye + refracts light
• no stem cells in damaged tissue
• inoculating loop = a sterile loop used to transfer bacteria onto an agar plate
• bacteria grows RAPIDLY at room temp
• boiling kills MOST bacteria
• aseptic = a sterile working technique that limits contamination from other microorganisms
• plating = growing a culture of bacteria on a sterile petri dish
• agar = a nutrient jelly used to grow cultures
• to sterilise equipment:

  • 'flaming' during experiment
  • or autoclaving before experiment
• boil agar jelly before use (then allow to cool)
• sterilise wire loop by 'flaming' and then placing near Bunsen (capital) burner flame
• antigens = proteins on the outside of cells and pathogens that cause your immune system to respond
• must autoclave plates + equipment after use for safety
• sweep inoculating loop across surface of agar careful not to dig in
• penicillium grows within fermenter -> secrets antibiotic penicillin into surrounding medium -> medium filtered and penicillin extracted
• colonies = high numbers of bacteria that have grown together
• conditions kept constant to ensure maximum growth of penicilium:

  • sterile air (oxygen for respiration)
  • sterile nutrients (glucose, amino acids + minerals)
  • optimum temp + pH
• clumping occurs if there are too many colonies on a plate -> difficult to estimate accurately colony forming units
• DNa has two backbones connected by bases
• complimentary base pairs =

  • thymine + adenine
  • guanine + cytosine
• ratio of complimentary base pairs same in every organism regardless of species but mass or % differs from species to species
• protein synthesis = amino acids join together to form protein -> order of amino acids determines which protein is made
• punett squares show possible genotype + phenotype outcomes of 2 organisms reproducing not number
• advantages of genetic engineering:

  • increased yield
  • grow in harsh conditions
  • resistance to disease
  • fewer insecticide sprays needed (make GM plants resistant to pests)