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2010-09-17 09:17:30

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  1. Major groups of organisms studied in microbiology
    • bacteria
    • algae
    • fungi
    • viruses
    • protozoa
  2. Bacteria (bacterium)
    • single celled
    • spherical rod
    • spiral shaped
    • a few forms filements
    • do not have cell nucleus
    • many gain nutrients from environment
    • some make their own by photosynthesis or other synthetic process
    • some move while some are stationary
  3. algae(alga)
    • single-cell microscopic organism
    • some marine algae are large and multicellular
    • has nucleus
    • photosynthesize their own food
  4. fungi (fungus)
    • single-celled microscopic organism
    • some are multi-cellular and macroscopic
    • example: mushroom
    • have nucleus
    • absorb ready-made nutrients from environment
  5. Viruses
    • are acellular, which makes them too small to be seen by a light microscope
    • they are composed of specific chemical substances
    • a nucleic acid, a few proteins
    • replicate themselves and show characteristics of other living cells
    • small acellular agents of disese are : viroids, pirons
    • viroids: casue plant disease- nucleic acid without a protein coating
    • pirons: cause cow disease-protein without any nucleic acid
  6. protozoa(protozoan)
    • single-cellular microscopic organism
    • with at least 1 nucleus
    • gets food by engulfing or ingesting smaller micro-organism
    • they can move; those that don't move cause human disease
    • they can be found in water and soil environments as well as animals
    • example: malarious mosquitoes
  7. bacterophage(phage)
    a virus that infects bacteria
  8. microorganism (microb)
    organisms studied with a microscope also includes viruses
  9. Cell theory
    • cells that are the fundamental units of life and carry out all the basic functions of living things
    • now it applies to all cellular organisms, but viruses
  10. germ theory of disease
    states that germs (microorganisms) can invade other organisms and cause disease
  11. spontaneous generation
    the theory that living organisms can arise from non-living things
  12. antibiotics
    a chemical substance that was produced to enter microorganisms that can inhibit the growth of destroy other microorganisms
  13. hypothesis
    a tentative explanation for an observed condition or event
  14. prediction
    the expected outcome if a hypothesism is correct
  15. experimental variable
    the factor that is purposly changed in an experiment
  16. control variable
    a factor that is prevented from changing during an experiment
  17. conclusion
    end result of an analysis of experimental result
  18. koch postulates
    • 1.) the specific causative agent must be found in every case of the disease
    • 2.) the disease organism must be isolated in pure culture
    • 3.) inoculation of a sample of the culture into a healthy susceptible animal must produce the same disease
    • 4.) the disease organism must be recovered from inoculated animal
  19. Microorganism are useful in research for at least 3 reasons:
    • 1.) microbs have simple structures. it is easier to study life process in simple unicellular organisms than in complex multicellular ones
    • 2.) Large number of microorganisms can be used in experiments at a reasonable cost, to obtain statistically reliable results
    • example: growing billions of bacteria is cheaper to maintain than 10 rats
    • 3.) microorganisms reproduce quickly, which maybe useful to studying the transfer of genetic information. some bacteria can undergo 3 cell division in 1 hour