Microscope Review
1. Give the name and
function of each
structure labeled.
A – Ocular lens/eyepiece:
used to look at specimen
B – Fine adjustment: to
focus specimen under
high power
C – Arm: to hold microscope
D – Objective lens: used to
magnify image
E – Coarse adjustment: to
focus specimen under low
power
F – Diaphragm – adjust
amount of light
E
F
2. What was the
highest possible
magnification that
can be obtained
when using this
microscope?
Highest:
• 40 x 10 = 400x
Lowest:
• 10 x 10 = 100x
E
F
3. What happens to
the amount of light
in the field of view
when switching
from low to high
power?
The amount of light
decreases (so the
field of view gets
darker)
E
F
4. What happens to the
field of view when
switching from low to
high power?
E
The field of view
decreases ( so you
see less of the
slide).
F
5. Which structure can
only be used to focus
the specimen under
high power? Support
your answer.
The fine adjustment
can only be used
because using the
coarse adjustment
under high power can
break the objective
lens or the slide.
E
F
6. What are two possible adjustments
that need to be made before
switching to high power?
1. Focus specimen
2. Center specimen
7. What happens to the number of cells
that are visible in the field of view
when switching to high power?
The number of cells that are visible in
the field of view decreases.
8. Which laboratory technique is
illustrated in the diagram?
• Preparing a wet mount.
9.Describe the steps to follow
when preparing a wet mount.
1. Place a drop of water on slide.
2. Place specimen on slide.
3. Place the cover slip at an angle.
4. Slowly lower the cover slip on to the
specimen.
10. Why must the cover slip be
placed at an angle when preparing
a wet mount?
To avoid air bubbles.
11. The diagram represents a cell in the field
of view of a compound light microscope. In
which direction should the slide be moved
on the microscope stage to center the cell
in the field of view?
Towards C
12. The image to the left is placed
on the slide. A student then views
the letter “f” under low power.
Which diagram below most closely
resembles the image under low
power?
13. A student sees the image to the
left when observing the letter "f"
with the low-power objective lens
of a microscope. Which diagram
below most closely resembles the
image the student will see after
switching to high power?
14. The total magnification of an
image is the result of the
combined magnifications of the
1) eyepiece and diaphragm
2) objective and eyepiece
3) objective and mirror
4) low-power and high-power
objectives
15. A student views some cheek cells
under low power. Before switching
to high power, the student should
(1) adjust the eyepiece
(2) center the image being viewed
(3) remove the slide from the stage
(4) remove the coverslip
16. A student changes the objective
of a microscope from 10x to 50x.
If this is the only change made,
what will happen to the field of
view?
(1) Its diameter will decrease.
(2) Its diameter will increase.
(3) Its brightness will increase.
(4) Its brightness will remain the
same.
17. A student determined that exactly 10
pollen grains could fit along the
diameter of the field of view of a
microscope. If each pollen grain has a
diameter of 200 micrometers, what is
the diameter in millimeters of this
microscope's field of view?
(1) 2,000 mm
(2) 2 mm
(3) 5 mm
(4) 500 mm
18. To locate a specimen on a prepared slide with a
compound microscope, a student should begin with
the low-power objective rather than the highpower objective because the
(1) field of vision is smaller under low power than
under high power
(2) field of vision is larger under low power than
under high power
(3) specimen does not need to be stained for
observation under low power but must be stained
for observation under high power
(4) amount of the specimen that can be observed
under low power is less than the amount that can be
observed under high power
19. An unstained wet mount
preparation of cheek cells shows
few details. Which substance could
be added to the slides to make the
details more visible?
(1) stain
(2) water
(3) Nothing should be added
20. After switching from the highpower to the low-power objective lens
of a compound light microscope, the
area of the low-power field will
appear
(1) larger and brighter
(2) smaller and brighter
(3) larger and darker
(4) smaller and darker
21. The diagram represents a hydra as viewed with a
compound light microscope. If the hydra moves to
the right of the slide preparation, which diagram
below best represents what will be viewed through
the microscope?
22. Which part of a microscope
should be used with the low power
objective, but not with the highpower objective?
a. fine adjustment
b. diaphragm
c. coarse adjustment
d. eyepiece
23. Which of the following describes proper
microscope care and technique.
a. Be sure to carry the microscope upright, with one
hand on the arm and the other under the base.
b. To protect the lenses of the microscope, place it
down gently and don't drag it across the tabletop.
c. Always begin focusing with the lowest power
objective lens available.
d. Only use the coarse focus knob with the low power
objective lenses.
e. All the above are examples of correct microscope
care and technique.
24. Which of the following regulates
the amount of light passing through
the slide specimen on the microscope
stage?
a. nosepiece
b. objective lens
c. diaphragm
d. fine adjustment knob
25. An increase in magnification
causes
a. a decrease in the field of view.
b. a decrease in the working distance.
c. a decrease in the depth of field.
d. all of the above.
26. When the letter e slide is viewed
with the microscope, it appears
a. right side up.
b. right side up and backwards.
c. upside down.
d. upside down and backwards.
27. Which part holds the two or three objective lenses, and
rotates around in a circle, allowing you to choose which
objective lens you want to use?
• nosepiece
28. What holds the upper portion of the microscope above
the stage and is also where you grab the microscope anytime
you decide to take it for a walk?
• arm
29. This part allows you to focus while using the high power
objective.
• fine adjustment knob
30. What holds the slide in place?
• stage clips
31. What's the long, skinny tube that holds the
eyepiece above the microscope, and allows light to
travel up from the objective lenses to the
eyepiece?
• body tube
32. What parts are attached to the nosepiece and
vary in size?
• Objective lenses
33. On what part of the microscope do you place
your specimen?
• stage
34. A prepared slide was placed on the stage
of a microscope so that the slide faced the
student, as shown in the diagram below.
Which image will the student most likely see?
35. How is the total magnification of a
microscope calculated?
• Eyepiece magnifications x objective lens
magnification
36. What is the total magnification
produced by a microscope, using a 10X
ocular lens and a 10X objective lens?
• 10 x 10
• 100x
37.
1. )
2. )
3. )
4. )
Convert:
6230
6.23mm = ______
um
5.678
5678um = ______
mm
93
0.093mm = ______
um
.0482
48.2um = ______
mm
38. The diagram represents the field of view
of a compound light microscope. Three
unicellular organisms are located across the
diameter of the field. What is the
approximate length of each unicellular
organism?
1) 250 um
2) 500 um 3) 1,000 um 4) 1,500 um
39. This organism could be centered in the
field of view by moving the microscope
slide towards
(1) A
(2) B
(3) C
(4) D
40. Determine the diameter of the field
of view below in millimeters and
micrometers.
3.5 mm
3500 um
41. Determine the diameter of the field
of view below in millimeters and
micrometers.
3.8 mm
3800 um
42. Determine the diameter of the field
of view below in millimeters and
micrometers.
5 mm
5000 um
43. Determine the diameter of the field
of view below in millimeters and
micrometers.
10 mm
10,000 um
44. Determine the diameter of the field
of view below in millimeters and
micrometers.
3.8 mm
3800 um
45. Determine:
• the diameter of the field of view below in millimeters
and micrometers
• The length of the specimen in the field of view
Diameter =
7.5 mm , 7500 um
Length of specimen =
4 mm , 4000 um
46. Determine the diameter of the field
of view below in millimeters and
micrometers.
5 mm , 5000 um
47. Determine the diameter of the field
of view below in millimeters and
micrometers.
2 mm , 2000 um
48. The diameter is 1mm. What is the
length of the cell?
0.25 mm
0.5 mm
0.25 mm, 250 um
49. The diameter is 3.5 mm. What is the
length of the cell?
1.75um
3.5mm
The length of the cell is approximately 1.75 mm,
1750um.
50. The diameter is 2000 um. What is the
length of the cell?
500 um
1000 um
2000 um
The length of the cell is approximately 500 um, 0.5
mm.
51. The diameter is 1800 um. What is the
length of the letter?
900 um, 0.9 mm
Diameter = 6 mm
52. What is the length of 1 cell?
6/3 = 2 mm
53. What is the length of
one cell?
400/4
= 100 um
0.1 mm
54.