BIOD 171 MODULE 3 EXAM QUESTION AND
ANSWER LATEST 2025-2026
QUESTION 1
A nanometer is defined as:
10 -9 or one-billionth of a meter
QUESTION 2
True or False: A nanometer is longer than a micrometer
False
A nanometer is 1000x smaller than a micrometer
QUESTION 3
Resolution and contrast are two critical factors that influence your ability to see an object. Explain each.
Resolution refers to the distance between two objects at which the objects can still be seen as
separate. Poor or low resolution means two or more objects may appear as one.
Contrast on the other hand 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 4
Assuming a fixed ocular, identify the part of the microscope you would adjust to enhance the
magnification of a sample.
Objective
Only the oculars (eyepiece) and the objectives contribute to the magnification of the sample. Since
the eyepiece
is fixed, only the objectives could be altered.
QUESTION 5
Assuming a constant (non-adjustable) light source power, identify the part of the microscope you would
adjust to limit the amount of light entering the microscope.
Iris diaphragm
QUESTION 6
What is the total magnification on (relative to your eye) of a sample imaged with a 60x objective and a
10x eyepiece? Show your math.
60x objective x 10x ocular = 600x magnification
QUESTION 7
True or False: Staining is often required to image a cell that is adherent and flat (thin).
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.
QUESTION 8
ANSWER LATEST 2025-2026
QUESTION 1
A nanometer is defined as:
10 -9 or one-billionth of a meter
QUESTION 2
True or False: A nanometer is longer than a micrometer
False
A nanometer is 1000x smaller than a micrometer
QUESTION 3
Resolution and contrast are two critical factors that influence your ability to see an object. Explain each.
Resolution refers to the distance between two objects at which the objects can still be seen as
separate. Poor or low resolution means two or more objects may appear as one.
Contrast on the other hand 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 4
Assuming a fixed ocular, identify the part of the microscope you would adjust to enhance the
magnification of a sample.
Objective
Only the oculars (eyepiece) and the objectives contribute to the magnification of the sample. Since
the eyepiece
is fixed, only the objectives could be altered.
QUESTION 5
Assuming a constant (non-adjustable) light source power, identify the part of the microscope you would
adjust to limit the amount of light entering the microscope.
Iris diaphragm
QUESTION 6
What is the total magnification on (relative to your eye) of a sample imaged with a 60x objective and a
10x eyepiece? Show your math.
60x objective x 10x ocular = 600x magnification
QUESTION 7
True or False: Staining is often required to image a cell that is adherent and flat (thin).
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.
QUESTION 8
