BIO 235 Microbiology Exam 1
Questions and Answers 100% pass
units of measurement - ✔✔1 µm = 10-6 m = 10-3 mm
1 nm = 10-9 m = 10-6 mm
1000 nm = 1 µm
0.001 µm = 1 nm
total magnification (compound microscopes) - ✔✔-the image from the
objective lens is
magnified again by the ocular lens
-total magnification = objective lens x ocular
lens
resolution - ✔✔-the ability of the lenses to distinguish two points.
1
100% Pass Guarantee Katelyn Whitman, All Rights
,-shorter wavelengths of light provide greater resolution
objective lens - ✔✔lens closest to the specimen
condenser - ✔✔focuses light onto the specimen
brightfield illumination microscopy - ✔✔-dark objects are visible against a
bright background
-light reflected off the specimen does not enter
the objective lens
-used for stained microbial cells
darkfield illumination microscopy - ✔✔-light objects are visible against a
dark background
-light reflected off the specimen enters the objective lens
-used for cells that do not stain easily
phase contrast microscopy - ✔✔-accentuates the diffraction of a light that
passes through a specimen
2
100% Pass Guarantee Katelyn Whitman, All Rights
, -to facilitate detailed examination of the internal structures of living
specimens
DI contrast microscopy - ✔✔-differential interference
-uses a polarizer to create two distinct beams of polarized light
-typically used on unstained
cells to reveal internal structures
-gives structures such as nucleus, endospores, vacuoles, and granules a
three-dimensional
appearance
fluorescence microscopy - ✔✔-used to visualize specimens that fluoresce,
emitting light of one color after absorbing light of different color
-some cells naturally fluoresce due to components like chlorophyll, but
others have to be stained with a fluorescent dye
-often rapidly used to detect and identify microbes in tissues or clinical
specimens as well as for enumerating bacteria in a natural environment
3
100% Pass Guarantee Katelyn Whitman, All Rights
Questions and Answers 100% pass
units of measurement - ✔✔1 µm = 10-6 m = 10-3 mm
1 nm = 10-9 m = 10-6 mm
1000 nm = 1 µm
0.001 µm = 1 nm
total magnification (compound microscopes) - ✔✔-the image from the
objective lens is
magnified again by the ocular lens
-total magnification = objective lens x ocular
lens
resolution - ✔✔-the ability of the lenses to distinguish two points.
1
100% Pass Guarantee Katelyn Whitman, All Rights
,-shorter wavelengths of light provide greater resolution
objective lens - ✔✔lens closest to the specimen
condenser - ✔✔focuses light onto the specimen
brightfield illumination microscopy - ✔✔-dark objects are visible against a
bright background
-light reflected off the specimen does not enter
the objective lens
-used for stained microbial cells
darkfield illumination microscopy - ✔✔-light objects are visible against a
dark background
-light reflected off the specimen enters the objective lens
-used for cells that do not stain easily
phase contrast microscopy - ✔✔-accentuates the diffraction of a light that
passes through a specimen
2
100% Pass Guarantee Katelyn Whitman, All Rights
, -to facilitate detailed examination of the internal structures of living
specimens
DI contrast microscopy - ✔✔-differential interference
-uses a polarizer to create two distinct beams of polarized light
-typically used on unstained
cells to reveal internal structures
-gives structures such as nucleus, endospores, vacuoles, and granules a
three-dimensional
appearance
fluorescence microscopy - ✔✔-used to visualize specimens that fluoresce,
emitting light of one color after absorbing light of different color
-some cells naturally fluoresce due to components like chlorophyll, but
others have to be stained with a fluorescent dye
-often rapidly used to detect and identify microbes in tissues or clinical
specimens as well as for enumerating bacteria in a natural environment
3
100% Pass Guarantee Katelyn Whitman, All Rights
