Microbiology 351 Exam 1 Flashcards - Set 3

  1. Eukaryotic microbes (Protozoa, algae, fungi) range in size from about:
    10-100 μm
  2. Prokarytoes (Bacteria, archaea) range in size from about:
    0.4-10 μm
  3. Put the following microscopes in order of lowest to highest power of range of resolution.
    - Scanning electron microscopy
    - Atomic force microscopy
    - Human eye
    - Transmission electron microscopy
    - X-ray crystallography
    - Light microscopy
    • 1. Human eye
    • 2. Light microscopy
    • 3. Scanning electron
    • 4. Transmission electron
    • 5. Atomic force
    • 6. X-ray crystallography

    Note: Scanning and Transmission electron can go up to the same power of resolution, but Scanning's lower range is much lower.
  4. Name the bacteria shape: Filamentous rods
  5. Name the bacteria shape: spheres
  6. Name the bacteria shape:unique bacterial shape that evlolved in only one taxon. A tightly coiled spiral.
  7. Range of visible light
    400-750 nm
  8. Put the following waves in order from longest to shortest length.
    - Visible
    - Microwaves
    - Gamma rays
    - Ultraviolet
    - Radio waves
    - Infrared
    - X-rays
    • 1. Radio
    • 2. Microwaves
    • 3. Infrared
    • 4. Visible
    • 5. Ultraviolet
    • 6. X-rays
    • 7. Gamma rays
  9. The smallest distance by which two objects can be separated and still be distinguished
  10. Resolution of the human retina
    ~150 μm
  11. The ability to determine the presence of an object
  12. An increase in the apparent size of an image to resolve smaller separations between objects
  13. The photon's energy is acquired by the absorbing object
  14. The light's wavefront bounces off the surface of an object
  15. The bending of light as it enters a substance that slows its speed
  16. Occurs when the light's wavefront interacts with an object smaller than the wavelength of light
  17. _______ by a lens, requires the bending of light rays, as in refraction.
  18. When light rays enter a parabolic lens, parallel rays each bend at an angle such that all of the rays meet at a certain point, called the:
    focal point
  19. It is ______, not magnification, that limits the ability of what we can see with a microscope.
  20. Magnification without increasing detail is called:
    empty magnification
  21. The resolution of detail in microscopy is limited by the _____ _____ of light.
    wave nature
  22. Light rays actually form wavefronts, which undergo _______, which can be constructive or destructive.
  23. Name four things that resolution depends on.
    • 1. Wavelength of light (smaller than object)
    • 2. Contrast between object and surroundings
    • 3. Lens quality and magnifying power
    • 4. Position of the focal plane
  24. Name the labeled parts of this microscope.
    Image Upload 1
    • A: Light source
    • B: Diaphragm
    • C: Condenser
    • D: Stage
    • E: Objectives on revolving nosepiece
    • F: Eyepiece
    • F: Focusing knob
  25. What's wrong with the focus?
    Image Upload 2
    Too close to lens; image is blurred
  26. What's wrong with the focus?
    Image Upload 3
    In focus; image appears sharp.
  27. What's wrong with the focus?
    Image Upload 4
    Too far beyond focal point; image appears "empty" with interference rings
  28. What's wrong with the focus?
    Image Upload 5
    Object extends through focal planes
  29. What kind of stain is methylene blue?
  30. Name the differential stain: bacteria retain the crystal violet stain because of their thicker cell wall
    Gram stain
  31. Gram-_____ appear purple because they ____ the crystal violet stain.
    positive, retain
  32. Gram-______ bacterial appear pink because they _____ the cyrstal violet stain.
    negative, don't retain
  33. Name the differential stain: Carbolfuchsin used to stain Mycobacterium species
    Acid-fast stain
  34. Name the differential stain: malachite green used to detect spores of Bacillus and Clostridium
    Spore stain
  35. Name the differential stain: colors the background, which makes capsules more visible
    Negative stain
  36. In fluorescence microscopy, the specimen absorbs light of a specific wavelength called the:
    excitation wavelength
  37. In flurescence microscopy, the specimen emits light at a longer wavelength called the:
    emission wavelength
  38. ____-____ microscopy enables microbes to be visualized as halos of bright light against darkness.
  39. Name the type of microscopy: 
    - Superimposes refracted light and transmitted light shifted out of phase
    - Difference in refractive index are seen as pattern of light and dark
    - Used to view live cells and organelles
    Phase-contrast microscopy
  40. Name the type of microscopy:
    Image Upload 6
    Fluorescence microscopy
  41. Name the type of microscopy:
    Image Upload 7
    Dark-field microscopy
  42. Name the type of microscopy:
    Image Upload 8
    Phase-Contrast microscopy
  43. Name the type of microscopy:
    - Sample coated with heavy metal to absorb electrons
    - Lenses are magnets, needs vacuum
    Electron microscopy
  44. Name the type of microscopy:
    - Electrons pass through the specimen
    - Embedded in a polymer for cutting with microtome (or sprayed onto a copper grid)
    - Reveals internal structures
    Transmission electron microscopy (TEM)
  45. Name the type of microscopy:
    - Electrons scan the specimen surface
    - Reveals external features in 3D
    Scanning electron microscopy (SEM)
  46. Name the type of microscopy:
    - Specimen in flash-frozen
    - Suspended in water and frozen rapidly in a refrigerant
    cryo-EM or electron cryomicroscopy
  47. Name the type of microscopy:
    - avoids the need to physically slice the sample for thin-section TEM
    - images are combined digitally to visualize the entire object in 3D
    Cryo-electron tomography, or electron cryotomography
  48. Name the type of microscopy:
    - enables nanoscale observation of cell suraces
    Scanning probe microscopy (SPM)
  49. Name the type of microscopy:
    - example of SPM
    - measures the van der Waals forces between electron shells of adjacent atoms of the cell surface and the sharp tip
    - can be used to observe live bacteria in water or exposed to air (unlike electron microscopy)
    atomic force microscope (AFM)
  50. Name the type of microscopy: employs various stains
  51. Name the type of microscopy: employs fluorophores for labeling
  52. Name the type of microscopy: detects unresolved objects
  53. Name the type of microscopy: exploits differences in refractive index
  54. Electron microscope that provides internal details in 2D
  55. Electron microscope that provides external detail in 3D
  56. Microbes include members of which of the following groups?

    C) Bacteria, archaea, fungi, viruses
  57. Lithrotrophs are ogranisms that feed on ______, and were discovered by _____.

    C) inorganic material; Sergei Winogradski
  58. Koch's postulates include all of the following EXCEPT:

    C) The pathogen must be shown to contain toxins.
Card Set
Microbiology 351 Exam 1 Flashcards - Set 3