Please note that the following review questions are mostly drawn from the required textbook chapters and
the lecture material. However, I reserve the right to examine you on anything that was said in lecture or in
lab, or included in the required reading for the course.
While the following questions will assist you in studying for exams, they are not designed to serve as a
substitute for regular class attendance, diligent reading, and active participation in labs
Chapter 1—Introduction
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The microbial world mainly consists of bacteria (which we spend the most time on), the
archaea (who superficially resemble bacteria but on a molecular level are vastly
different), the viruses (which can infect eukaryotic and prokaryotic cells) and the protists
(single-celled eukaryotic organisms). What are the three domains of life? What domain
are viruses in?
What are the main differences between prokaryotes and eukaryotes?
Although bacteria and archaea are both prokaryotes, it is estimated they diverged around
3.5 billion years ago (meaning the last common ancestor for all life on earth was likely
3.5 billion years ago). Which group are we more related to?
Organisms in the microbial world are important for many reasons: For example, bacteria
and yeast are responsible for the products of fermentation such as alcohol. Can you think
of other reasons bacteria and other microorganisms are important? How have they
improved our lives (or made living possible)? How have they caused humans problems?
Who first observed cells under the microscope? Who first observed bacteria?
You should know who Louis Pasteur was and understand his experiment that refuted the
notion of spontaneous generation (the swan-neck flask experiment). Can you explain this
experiment? What is germ theory?
You should know who Robert Koch was and understand Koch’s postulates. Also, it is
important to understand the limitations of Koch’s postulates based on our current
understanding of microbiology. Why was Koch’s work so important to the idea that
microorganisms cause disease and not supernatural causes?
Understand the difference between a light microscope and an electron microscope, most
important is that an electron microscope uses an electron beam to take an image. Why
can an electron microscope take images at much higher magnification than a light
microscope?
Chapter 3
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While we did talk about eukaryotic cells, the focus was on bacterial cells.
You should be able to identify (with the correct terminology) different bacterial shapes
and understand the bacteria maintains its shape via the cell wall. How does cell shape
differ from cell arrangement?
Capsule is made by many bacteria and can be important in protecting the bacteria from
the environment. Why might bacteria make a capsule?
What makes up the different components of a Gram negative and Gram positive bacterial
cell? Which would be more sensitive to penicillin and why?
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Both types of bacteria have a cell membrane underneath the peptidoglycan layer. It is
very similar to the cell membrane of eukaryotic cells. What is the fluid-mosaic model of
the cell membrane? Is the membrane permeable?
You should understand that some transport of molecules across the membrane does not
take energy (diffusion) but some transport does take energy (active transport). You
should know when active transport is necessary (concentration gradients). What is
osmosis? When does water flow into or out of a cell?
How do bacteria move? What causes the “run”? What causes the “tumble”? You should
understand the idea of chemotaxis and that bacteria can sense the outside world and
respond to it. This is also an important point in Chapter 7 (and the lac operon).
Pili (pilus) are important for bacteria attachment. You should have some idea of why this
might be important to bacteria. What is the purpose of the sex pilus?
Bacteria DNA (the chromosome) is circular and extrachromosomal DNA can exist in the
form of a circular plasmid. Bacteria also contain storage granules.
When the environment is harsh, some bacteria can create an endospore. How is an
endospore different from a regular (called vegetative) cell? Why would bacteria create an
endospore?
You should know how the eukaryotic cell takes up material from the outside world and
that they can also be motile (flagella and cilia).
The mitochondria are the power plant of the cell. What is the endosymbiotic theory and
what is the evidence that supports this theory?