CELL BIOLOGY (BIO 311) EXAM 1 STUDY GUIDE QUESTIONS AND ANSWERS
2026/2027 | COMPLETE EXAM REVIEW
The foundation of Cell Biology - ANS ✔✔The Light Microscope
Robert Hooke - ANS ✔✔coined the term "cell" in 1665.
Antony Van Leeuwenhoek - ANS ✔✔Protozoa, Bacteria (1674)
Schleiden & Schwann - ANS ✔✔Cell Theory; regarded as the founders of cell biology.
Reticular Theory - ANS ✔✔Nerve cells were not cells; neurons are a part of a reticulum
somewhat like the vascular system.
E.g. Vascular Network - Not cells.
Neuronal Theory - ANS ✔✔Neurons are really cells.
Resolving Power - ANS ✔✔Limited by the wavelength of the illuminating source.
Light Microscopes - ANS ✔✔Light resolution as we can see it is limited to 0.2 μm.
Electron Microscopes - ANS ✔✔Limit 2.4Å
Two major choices for microscopy in general: - ANS ✔✔a. Which microscope to select?
b. How to process cells/tissue?
,Why aren't light microscopes capable of resolving capabilities similar to electron
microscopes? - ANS ✔✔All microscopes are considered either "diffraction limited" or "not
diffraction limited" with the latter referring to "Super Resolution Microscopy."
Resolution - ANS ✔✔The capability of seeing 2 separate entities as 2 separate entities rather
than a single subject.
Not the same as "enlargement"
Abbe = Abbe's Equation
Theoretical Limit Of Resolution - ANS ✔✔Dictated by the optics of the microscope, i.e. the best
resolution one could have by optimizing everything.
Best possible resolution.
Can be calculated by Abbe's equation.
Practical Limit of Resolution - ANS ✔✔What you really get; it is what you really can't attain
depending on other factors that influence the theoretical limit of resolution.
- Thickness, organic materials that absorb heat, lack of contrast, etc. → DECREASE RESOLUTION
- But, computer enhancement in averaging can INCREASE RESOLUTION
,Cells = Poor Candidates
Mostly made of water; low density → very inherent
contrast
Section: in order to look at cells, tissue or cell has to be thick; 10 to 15 μm
Organic compounds: love to absorb radiation; generated heat, and samples will show thermal
movement.
Abbe's Equation - ANS ✔✔A formula that dictates the theoretical limit of resolution for both
light and electron microscopes.
d = 0.61λ/nsinθ
1800's Carl Zeiss; Abbe
Super Resolution Microscopy - ANS ✔✔NOT limited by Abbe's Equation
Dyes - 2 types - ANS ✔✔Colorimetric and Fluorochromes.
Colorimetric Dye - ANS ✔✔Absorb different wavelengths and transmit others; such as
hematoxylin (nucleus) and eosin (cytoplasm) which are dyes that can be detected using the
visible spectrum of light.
Fluorochromes - ANS ✔✔Fluorescent Dye → have much more utility than colorimetric probes
as they can absorb certain wavelengths and emit light.
, Contrast is a problem. Solutions are the following: - ANS ✔✔1. Dyes
2. Manipulating light
3. Computer Image Enhancement
Manipulating Light to fix contrast - ANS ✔✔Can manipulate the light that is going through the
cells so that it generates contrast.
Both the Phase Contrast and Nomarski Optics (DIC) systems generate contrast in living cells
through manipulating the light paths as they travel through the specimen. Excellent systems for
viewing living cells.
Computer Image Enhancement to fix contrast - ANS ✔✔Can take the image of dyed cells and
make them even better.
This is variable depending on the type of microscope, but it is used for PALM, Deconvolution
Microscopy, and Super Resolution Microscopy.
Run through algorithm.
Bright-Field Microscopy - ANS ✔✔First developed by Carl Zeiss and Abbe; most commonly used
one today even though it is the oldest.
Who would use Bright-Field Microscopy? - ANS ✔✔1. Pathologists
2. Cytochemists (looking for certain aspects of the cell)
3. Histologists/Histochemist → Tissue Sections
Bright-Field Microscopy - Process - ANS ✔✔1. Fixation → Kill the cells
2026/2027 | COMPLETE EXAM REVIEW
The foundation of Cell Biology - ANS ✔✔The Light Microscope
Robert Hooke - ANS ✔✔coined the term "cell" in 1665.
Antony Van Leeuwenhoek - ANS ✔✔Protozoa, Bacteria (1674)
Schleiden & Schwann - ANS ✔✔Cell Theory; regarded as the founders of cell biology.
Reticular Theory - ANS ✔✔Nerve cells were not cells; neurons are a part of a reticulum
somewhat like the vascular system.
E.g. Vascular Network - Not cells.
Neuronal Theory - ANS ✔✔Neurons are really cells.
Resolving Power - ANS ✔✔Limited by the wavelength of the illuminating source.
Light Microscopes - ANS ✔✔Light resolution as we can see it is limited to 0.2 μm.
Electron Microscopes - ANS ✔✔Limit 2.4Å
Two major choices for microscopy in general: - ANS ✔✔a. Which microscope to select?
b. How to process cells/tissue?
,Why aren't light microscopes capable of resolving capabilities similar to electron
microscopes? - ANS ✔✔All microscopes are considered either "diffraction limited" or "not
diffraction limited" with the latter referring to "Super Resolution Microscopy."
Resolution - ANS ✔✔The capability of seeing 2 separate entities as 2 separate entities rather
than a single subject.
Not the same as "enlargement"
Abbe = Abbe's Equation
Theoretical Limit Of Resolution - ANS ✔✔Dictated by the optics of the microscope, i.e. the best
resolution one could have by optimizing everything.
Best possible resolution.
Can be calculated by Abbe's equation.
Practical Limit of Resolution - ANS ✔✔What you really get; it is what you really can't attain
depending on other factors that influence the theoretical limit of resolution.
- Thickness, organic materials that absorb heat, lack of contrast, etc. → DECREASE RESOLUTION
- But, computer enhancement in averaging can INCREASE RESOLUTION
,Cells = Poor Candidates
Mostly made of water; low density → very inherent
contrast
Section: in order to look at cells, tissue or cell has to be thick; 10 to 15 μm
Organic compounds: love to absorb radiation; generated heat, and samples will show thermal
movement.
Abbe's Equation - ANS ✔✔A formula that dictates the theoretical limit of resolution for both
light and electron microscopes.
d = 0.61λ/nsinθ
1800's Carl Zeiss; Abbe
Super Resolution Microscopy - ANS ✔✔NOT limited by Abbe's Equation
Dyes - 2 types - ANS ✔✔Colorimetric and Fluorochromes.
Colorimetric Dye - ANS ✔✔Absorb different wavelengths and transmit others; such as
hematoxylin (nucleus) and eosin (cytoplasm) which are dyes that can be detected using the
visible spectrum of light.
Fluorochromes - ANS ✔✔Fluorescent Dye → have much more utility than colorimetric probes
as they can absorb certain wavelengths and emit light.
, Contrast is a problem. Solutions are the following: - ANS ✔✔1. Dyes
2. Manipulating light
3. Computer Image Enhancement
Manipulating Light to fix contrast - ANS ✔✔Can manipulate the light that is going through the
cells so that it generates contrast.
Both the Phase Contrast and Nomarski Optics (DIC) systems generate contrast in living cells
through manipulating the light paths as they travel through the specimen. Excellent systems for
viewing living cells.
Computer Image Enhancement to fix contrast - ANS ✔✔Can take the image of dyed cells and
make them even better.
This is variable depending on the type of microscope, but it is used for PALM, Deconvolution
Microscopy, and Super Resolution Microscopy.
Run through algorithm.
Bright-Field Microscopy - ANS ✔✔First developed by Carl Zeiss and Abbe; most commonly used
one today even though it is the oldest.
Who would use Bright-Field Microscopy? - ANS ✔✔1. Pathologists
2. Cytochemists (looking for certain aspects of the cell)
3. Histologists/Histochemist → Tissue Sections
Bright-Field Microscopy - Process - ANS ✔✔1. Fixation → Kill the cells
