Question 1
pts
A micrometer is defined as:
A. 10-3
B. 10-6
C. 10-9
D. 10-12
Question 2
pts
Resolution and contrast are two critical factors that influence your ability to see
an object. Explain each.
Your Answer:
, Resolution refers to the distance between two objects at which the
objects still can be seen as separate. Poor or low resolution means two
(or more) objects may appear as one.
Contrast is the difference in light absorbance between two objects. Poor
contrast gives a high background and makes the visualization of multiple
objects difficult. For instance, trying to identify 2 dark colored objects at
night (low light = low contrast) versus the same 2 objects in the middle of
a sunny afternoon (bright light against 2 dark objects = high contrast).
Question 3
pts
Assuming a fixed ocular, identify the part of the microscope you would adjust to
enhance the magnification of a sample.
Eye piece
IIris diaphragm
Objective
Condenser
Question 4
, pts
What is the total magnification (relative to your eye) of a sample imaged with a
20x objective and a 15x eyepiece? Show your math.
Your Answer:
20 x 15 = 300x magnification
Question 5
pts
True or False: Staining is often required to image a cell that is adherent and flat
(thin).Correct!
True
Adherent, flat and unstained cells are almost invisible due to the limits on both resolution
and contrast. Therefore, cell staining is often required to adequately image the sample.
False
Question 6
pts
, Which of the following could NOT be seen clearly by the unaided eye? Select all
that apply.
Virus with a diameter of 0.2 μm
Protozoa with diameter of 150 μm
Bacteria with diameter of 24 μm
Skin cell with diameter of 1500 μm
A and C. The unaided eye can, on average, clearly resolve objects > 100
μm
Question 7
pts
Label the following unmarked microscope components (numbered arrows) by
matching it with the components provided (letters).
pts
A micrometer is defined as:
A. 10-3
B. 10-6
C. 10-9
D. 10-12
Question 2
pts
Resolution and contrast are two critical factors that influence your ability to see
an object. Explain each.
Your Answer:
, Resolution refers to the distance between two objects at which the
objects still can be seen as separate. Poor or low resolution means two
(or more) objects may appear as one.
Contrast is the difference in light absorbance between two objects. Poor
contrast gives a high background and makes the visualization of multiple
objects difficult. For instance, trying to identify 2 dark colored objects at
night (low light = low contrast) versus the same 2 objects in the middle of
a sunny afternoon (bright light against 2 dark objects = high contrast).
Question 3
pts
Assuming a fixed ocular, identify the part of the microscope you would adjust to
enhance the magnification of a sample.
Eye piece
IIris diaphragm
Objective
Condenser
Question 4
, pts
What is the total magnification (relative to your eye) of a sample imaged with a
20x objective and a 15x eyepiece? Show your math.
Your Answer:
20 x 15 = 300x magnification
Question 5
pts
True or False: Staining is often required to image a cell that is adherent and flat
(thin).Correct!
True
Adherent, flat and unstained cells are almost invisible due to the limits on both resolution
and contrast. Therefore, cell staining is often required to adequately image the sample.
False
Question 6
pts
, Which of the following could NOT be seen clearly by the unaided eye? Select all
that apply.
Virus with a diameter of 0.2 μm
Protozoa with diameter of 150 μm
Bacteria with diameter of 24 μm
Skin cell with diameter of 1500 μm
A and C. The unaided eye can, on average, clearly resolve objects > 100
μm
Question 7
pts
Label the following unmarked microscope components (numbered arrows) by
matching it with the components provided (letters).
