PORTAGE MICROBIOLOGY LECTURE
EXAM 3 QUESTIONS WITH 100%
CORRECT ANSWERS L LATEST
VERSION 2025/2026.
micrometer - ANS one millionth of a meter
nanometer - ANS one billionth of a meter
two critical factors that influence our ability to see an object - ANS resolution and contrast
resolution - ANS the distance between two objects at which the objects still can be seen as
separate
contrast - ANS the difference in light absorbance between two (objects)
the closer two objects are to each other the __________________ the resolution requirement -
ANS greater
the ________________ the contrast between an object and its background, the harder it will be
to see the object - ANS lower
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, bright field microscope - ANS simplest form of light, or optical, microscopy/light, most often
emitted from a standard halogen bulb, enters the microscope from the base (bottom) and is
reflected via mirrors towards the sample
before the light reaches the sample, it first passes through a ________________ converging the
light beams into a focused area on the sample - ANS condenser
iris diaphragm - ANS controls the amount of light that passes through the sample and into
the objective lens
objective lens - ANS the lens closest to the sample and yields the greatest amount of
magnification
the degree of magnification is ______________________ to the amount of light needed/to
image samples clearly at higher magnifications, more light is required - ANS directly
proportional
ocular lens - ANS eyepiece
10x - ANS most common power of ocular lens
total magnification - ANS objective x ocular lens=
staining - ANS required due to the limitation of resolution on unstained cells, (i.e.) often the
flat and transparent regions of a cell may appear invisible under bright field conditions/with
various dyes, these regions can become labeled and thus visualized.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
EXAM 3 QUESTIONS WITH 100%
CORRECT ANSWERS L LATEST
VERSION 2025/2026.
micrometer - ANS one millionth of a meter
nanometer - ANS one billionth of a meter
two critical factors that influence our ability to see an object - ANS resolution and contrast
resolution - ANS the distance between two objects at which the objects still can be seen as
separate
contrast - ANS the difference in light absorbance between two (objects)
the closer two objects are to each other the __________________ the resolution requirement -
ANS greater
the ________________ the contrast between an object and its background, the harder it will be
to see the object - ANS lower
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, bright field microscope - ANS simplest form of light, or optical, microscopy/light, most often
emitted from a standard halogen bulb, enters the microscope from the base (bottom) and is
reflected via mirrors towards the sample
before the light reaches the sample, it first passes through a ________________ converging the
light beams into a focused area on the sample - ANS condenser
iris diaphragm - ANS controls the amount of light that passes through the sample and into
the objective lens
objective lens - ANS the lens closest to the sample and yields the greatest amount of
magnification
the degree of magnification is ______________________ to the amount of light needed/to
image samples clearly at higher magnifications, more light is required - ANS directly
proportional
ocular lens - ANS eyepiece
10x - ANS most common power of ocular lens
total magnification - ANS objective x ocular lens=
staining - ANS required due to the limitation of resolution on unstained cells, (i.e.) often the
flat and transparent regions of a cell may appear invisible under bright field conditions/with
various dyes, these regions can become labeled and thus visualized.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
