Microbiology LAB Exam #1 Questions
and Answers 100% Pass
Microscope- The Condenser - ✔✔focuses the light ging into the objective
lens
Microscope- The Iris Diaphragm - ✔✔adjusts the amount of light going
into the objective lens
Microscope- Nosepiece - ✔✔holds the objective lenses and rotates to
change from one objective to another
Microscope- Coarse Objective Knob - ✔✔moves the stage larger distances
to help get the object in focus
Microscope- Fine Adjustment Knob - ✔✔moves the stage smaler
increments to help get the object in better focus
1
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,Microscope- Objective Lens - ✔✔magnifies the object. It is located near the
object.
Microscope- Occular Lens - ✔✔magnifies the image of the object from the
objective lens. It is located near the eye.
Steps in using the microscope - ✔✔1) scanner power in place
2) place slide of specimen stage in place with stage clips
3) Using the course adjustment knob, raise the stage all the way up and
then down slowly until you can see image of specimen
4) Readjust with fine adjustment knob
Describe the purpose of the oil immersion lens - ✔✔Used when oil is added
to the slide. Oil must touch the object and objective lens to that the light
does not refract futher
Parfocal - ✔✔Parfocal microscopes are able to move from one objective to
the next and still be in focus due to the length of the objective lenses
Resolution - ✔✔The ability to distinguish between two objects that are very
close together.
2
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, What is resolving power? - ✔✔The measurement of resolution
What are two ways to increase resolving power? - ✔✔1. By decreasing the
wavelength of light (using a blue filter) 2. Increasing the numerical
aperature
What units are used to express resolving power? - ✔✔nm or nanometers
What is better, smaller or larger resolving power? - ✔✔Smaller is better
Light microscopes have a 200nm resolving power
Electron microscopes have a .2nm resolving power
What is chromatic aberration? - ✔✔The effect when many colors are seen
toward the edge of the microscope field of vision (like a prisim)
How are microscopes corrected for chromatic aberration? - ✔✔With a
special achromatic lens (corrected for red and blue light) or by using a blue
filter. The lab has blue filters in their microscopes which also increase
resolution.
3
100% Pass Guarantee Katelyn Whitman, All Rights
and Answers 100% Pass
Microscope- The Condenser - ✔✔focuses the light ging into the objective
lens
Microscope- The Iris Diaphragm - ✔✔adjusts the amount of light going
into the objective lens
Microscope- Nosepiece - ✔✔holds the objective lenses and rotates to
change from one objective to another
Microscope- Coarse Objective Knob - ✔✔moves the stage larger distances
to help get the object in focus
Microscope- Fine Adjustment Knob - ✔✔moves the stage smaler
increments to help get the object in better focus
1
100% Pass Guarantee Katelyn Whitman, All Rights
,Microscope- Objective Lens - ✔✔magnifies the object. It is located near the
object.
Microscope- Occular Lens - ✔✔magnifies the image of the object from the
objective lens. It is located near the eye.
Steps in using the microscope - ✔✔1) scanner power in place
2) place slide of specimen stage in place with stage clips
3) Using the course adjustment knob, raise the stage all the way up and
then down slowly until you can see image of specimen
4) Readjust with fine adjustment knob
Describe the purpose of the oil immersion lens - ✔✔Used when oil is added
to the slide. Oil must touch the object and objective lens to that the light
does not refract futher
Parfocal - ✔✔Parfocal microscopes are able to move from one objective to
the next and still be in focus due to the length of the objective lenses
Resolution - ✔✔The ability to distinguish between two objects that are very
close together.
2
100% Pass Guarantee Katelyn Whitman, All Rights
, What is resolving power? - ✔✔The measurement of resolution
What are two ways to increase resolving power? - ✔✔1. By decreasing the
wavelength of light (using a blue filter) 2. Increasing the numerical
aperature
What units are used to express resolving power? - ✔✔nm or nanometers
What is better, smaller or larger resolving power? - ✔✔Smaller is better
Light microscopes have a 200nm resolving power
Electron microscopes have a .2nm resolving power
What is chromatic aberration? - ✔✔The effect when many colors are seen
toward the edge of the microscope field of vision (like a prisim)
How are microscopes corrected for chromatic aberration? - ✔✔With a
special achromatic lens (corrected for red and blue light) or by using a blue
filter. The lab has blue filters in their microscopes which also increase
resolution.
3
100% Pass Guarantee Katelyn Whitman, All Rights
