BIOD 171 PORTAGE LEARNING FINAL EXAM QUESTIONS AND 100% CORRECT ANSWERS|2025/2026

BIOD 171 PORTAGE LEARNING FINAL EXAM
QUESTIONS AND 100% CORRECT
ANSWERS|2025/2026
A nanometer is defined as: - ANSWER-
B B B B B B 10 -9 or one-billionth of a meter
B B B B B B




True or False: A nanometer is longer than a micrometer - ANSWER-
B B B B B B B B B B B False



A nanometer is 1000x smaller than a micrometer
B B B B B B B




Resolution and contrast are two critical factors that influence your ability to see an object. Exp
B B B B B B B B B B B B B B B



lain each. - ANSWER-
B B B



Resolution refers to the distance between two objects at which the objects can still be s
B B B B B B B B B B B B B B B



een as separate. Poor or low resolution means two or more objects may appear as one.
B B B B B B B B B B B B B B B




Contrast on the other hand is the difference in light absorbance between two objects. Poor co
B B B B B B B B B B B B B B B



ntrast gives a high background and makes the visualization of multiple objects difficult. For ins
B B B B B B B B B B B B B B



tance, trying to identify 2 dark colored objects at
B B B B B B B B




night (low light = low contrast) versus the same 2 objects in the middle of
B B B B B B B B B B B B B B




a sunny afternoon (bright light against 2 dark objects = high contrast).
B B B B B B B B B B B




Assuming a fixed ocular, identify the part of the microscope you would adjust to enhance the
B B B B B B B B B B B B B B B B



magnification of a sample. - ANSWER- B B B B B Objective



Only the oculars (eyepiece) and the objectives contribute to the magnification of the sample.
B B B B B B B B B B B B B B



Since the eyepiece
B B




is fixed, only the objectives could be altered.
B B B B B B B




Assuming a constant (non- B B B



adjustable) light source power, identify the part of the microscope you would adjust to limit th
B B B B B B B B B B B B B B B



e amount of light entering the microscope. - ANSWER-
B B B B B B B B Iris diaphragm
B

, What is the total magnification on (relative to your eye) of a sample imaged with a 60x objecti
B B B B B B B B B B B B B B B B B



ve and a 10x eyepiece? Show your math. - ANSWER-
B B B B B B B B B



60x objective x 10x ocular = 600x magnification
B B B B B B B




True or False: Staining is often required to image a cell that is adherent and flat (thin). -
B B B B B B B B B B B B B B B B B



B ANSWER- True



Adherent, flat and unstained cells are almost invisible due to the limits on both
B B B B B B B B B B B B B




resolution and contrast. Therefore, cell staining is often required to adequately image
B B B B B B B B B B B




the sample. B




True or False: A cell that is adherent, flat (thin), and unstained is easily identified using bright fi
B B B B B B B B B B B B B B B B B



eld microscopy - ANSWER-
B B B



False: Adherent, flat cells are almost invisible due to the limits on both resolution and c
B B B B B B B B B B B B B B B



ontrast



Which of the following could be seen clearly by the unaided eye? Select all that apply.
B B B B B B B B B B B B B B B




A. Bacteria with diameter of 24 μm
B B B B B B




B. Protozoa with diameter of 150 μm
B B B B B B




C. Virus with a diameter of 0.2 μm
B B B B B B B




D. Skin cell with diameter of 1500 μm - ANSWER-
B B B B B B B B B B. Protozoa with diameter of 150 μm
B B B B B B




D. Skin cell with diameter of 1500 μm
B B B B B B B




The unaided eye can, on average, clearly resolve objects > 100 μm
B B B B B B B B B B B




2. Which of the following could NOT be seen clearly by the unaided eye? Select all that apply.
B B B B B B B B B B B B B B B B B




A. Bacteria with diameter of 24 μm
B B B B B B




B. Protozoa with diameter of 150 μm
B B B B B B