BIOD 171 Exam 3 Study
Study online at https://quizlet.com/_hntjyf
1. True or False: A nanometer (10-9) is longer than a micrometer (10-6).: False; A
nanometer is 1,000 times smaller than a micrometer.
2. Resolution and contrast are two critical factors that influence your ability to
see an object. Explain each.: Resolution is the difference in distance between two objects that appear as
two separate objects.
Contrast is the difference in light absorption by an object.
3. 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
4. What is the total magnification (relative to your eye) of a sample imaged with
a 60x objective and a 10x eyepiece? Show your math.: 60 x 10 = 600x magnification
5. True or False: Staining is often required to image a cell that is adherent and
flat (thin).: True
6. Which of the following could NOT be seen clearly by the unaided eye? Select
all that apply.: Bacteria with diameter of 24 μm
Virus with a diameter of 0.2 μm
7. This type of microscope utilizes ultraviolet (UV) light to illuminate stained
objects.: Fluorescence
8. This type of microscope can provide detailed images of live cells without
staining.: Phase-Contrast
9. This type of microscope enhances contrast between specimen and back-
ground but does not permit the visualization of intracellular structures.: Dark Field
10. This type of microscope is capable of capturing images in multiple focal
planes, rendering a specimen in 3-D.: Confocal
11. Identify what type of electron microscope was used to capture the following
image and explain your choice.: SEM. It appears that the electrons reflected off of the sample creating
a shell. Only TEM is capable of visualizing subcellular substrucutres.
12. Gram-Positive cells appear [answer1] in color due to a [answer2] peptidogly-
can layer in the cell wall.: 1. Purple
2. Thick
1/3
Study online at https://quizlet.com/_hntjyf
1. True or False: A nanometer (10-9) is longer than a micrometer (10-6).: False; A
nanometer is 1,000 times smaller than a micrometer.
2. Resolution and contrast are two critical factors that influence your ability to
see an object. Explain each.: Resolution is the difference in distance between two objects that appear as
two separate objects.
Contrast is the difference in light absorption by an object.
3. 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
4. What is the total magnification (relative to your eye) of a sample imaged with
a 60x objective and a 10x eyepiece? Show your math.: 60 x 10 = 600x magnification
5. True or False: Staining is often required to image a cell that is adherent and
flat (thin).: True
6. Which of the following could NOT be seen clearly by the unaided eye? Select
all that apply.: Bacteria with diameter of 24 μm
Virus with a diameter of 0.2 μm
7. This type of microscope utilizes ultraviolet (UV) light to illuminate stained
objects.: Fluorescence
8. This type of microscope can provide detailed images of live cells without
staining.: Phase-Contrast
9. This type of microscope enhances contrast between specimen and back-
ground but does not permit the visualization of intracellular structures.: Dark Field
10. This type of microscope is capable of capturing images in multiple focal
planes, rendering a specimen in 3-D.: Confocal
11. Identify what type of electron microscope was used to capture the following
image and explain your choice.: SEM. It appears that the electrons reflected off of the sample creating
a shell. Only TEM is capable of visualizing subcellular substrucutres.
12. Gram-Positive cells appear [answer1] in color due to a [answer2] peptidogly-
can layer in the cell wall.: 1. Purple
2. Thick
1/3
