Quiz Review 1

• Major classifications of microbes

  • Bacteria
  • Fungus
  • Protozoans
  • Viruses
• Viruses, Prions and Viroid's

  Considered microbes, but not considered to be microorganisms. They aren't technically alive because they aren't cellular or capable of many of the processes that are needed to be considered life.
• Advantages of bacteria's lack of complexity


  • Diversity
  • Survivability
  • Adaptability
• Weaknesses of bacteria's lack of complexity

  • Restricted to simple single celled life
  • Genetic variation is difficult due to lack of sexual reproduction
• Protozoans


  Animal-like: lack of a cell wall, motility, Ingestion of nutrients
• Fungus


  Plant-like: Have a cell wall, lack motility, Absorb nutrients
• Theories on the origins of life in the 17th and 18th centuries

  • Abiogenesis (spontaneous generation) = Life will form if the proper components and conditions are present
  • Biogenesis – All cells arise from other cells
• Biogenesis was the theory on the origins of life that was eventually widely accepted by the scientific field
• Pasteur was credited with settling the debate on the origins of life
• Cell theory (initial)


  Supported abiogenesis; the initial 3rd principle supported that
• Cell theory (revised by Virchow)


  Supported biogenesis; the revised third principle supported that
• Supporting principles added later to cell theory

  • Genetics are passed down trough heredity in DNA
  • The genetic code is the same "language" (universal) throughout life
  • The core of all metabolisms for life is glycolysis
  • Biological molecules serve similar functions throughout life
• Robert Koch's Postulates (Germ Theory of Disease)

  1. Find an organism who died of an infectious disease

  2. Isolate the pathogen from the dead specimen, and grow it into pure colonies

  3. Introduce the potential pathogen into an un infected organism, to see if the organism contracts the disease

  4. If successful reisolate and identify the organism initially isolated

  5. If the organism that Was reisolated was the organism that was originally isolated, then this was the pathogen
• Alexander Fleming was credited with discovering penicillin
• The discovery of antibiotics was not met with much enthusiasm initially due to lack of demand and failure to mass produce
• Edward Jenner was credited with the first vaccination, which was targeted at smallpox
• Jenner's thought process behind why the vaccine would work

  Exposure to a similar, but less virulent disease, wil convey immunity to the more severe disease
• Jenner would be arrested for testing the vaccine on a human child in the modern era
• John Lister was the first medical professional to widely use a disinfectant/antiseptic on his patients during surgeries
• Lister's method resulted in a 200% drop in hospital acquired infections (from 45% to 15%)
• The major drawback of Lister's practices with Phenol as an antiseptic was that it was very toxic to kidneys, brain and liver, especially if inhaled
• Other innovations enlisted as a result of Lister's revelation


  • PPE
  • Tracking
  • Health department protocols
  • Disinfection standards
• Top 3 causes of death in 1900

  • Diarrhea/enteritis
  • Influenza/pneumonia
  • Tuberculosis
• Top 3 causes of death in 1997

  • Heart disease
  • Cancer
  • Stroke
• The significance of the change in causes of death is that diseases of the aging are now more common than infectious disease deaths
• Major driving forces for emerging infectious diseases

  • Changes to the Pathogen (mutations, zoonotic transmission, resistance)
  • Ease of World Travel
  • Invasion into pathogens endemic area's
  • Lack of awareness about disease severity and vaccines