BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
There are two cell types - prokaryotic and eukaryotic. List the 7 classes or basic types of microorganisms
and identify each as prokaryotic, eukaryotic, both prokaryotic and eukaryotic, or neither. - (ANSWER)1.
Bacteria- prokaryotic
2. Archaea- prokaryotic
3. Algae- eukaryotic
4. Fungi- eukaryotic
5. Protozoa- eukaryotic
6. Helminthes- eukaryotic
7. Viruses- neither
What is a bacterial endospore? Explain how endospore-forming bacteria could cause a scientist to
believe in spontaneous generation. - (ANSWER)A bacterial endospore is an organism that is able to
survive in extreme conditions due to their tough structure.
Endospore-forming bacteria could cause scientists to believe in spontaneous generation because, they
can survive in extreme conditions that would normally kill bacteria. In spontaneous generation, it is said
that living things appear from vital forces existing in nonliving or decomposing matter, but there could
be bacterial endospore living in that situation without the scientists knowing.
Describe how organisms are placed in the Three Domain (Woese-Fox) classification system vs how
organisms are placed in the Five Kingdom (Traditional Wittaker) classification system. Which
classification system is more useful to a microbiologist and why? - (ANSWER)Organisms are placed in the
Three Domain classification system by using the three main branches, "Bacteria," Archaea," and
"Eukarya." They are placed in each domain based on what kind of cell they are (eukaryotic and
prokaryotic). Although prokaryotic cells are both Domain Bacteria and Domain Archaea, the members of
the Domain Archaea are very different from the ones in Domain Bacteria as they are able to live in
severe environments and are also able to produce metabolic byproducts.
Organisms are placed in the Five Kingdom classification system by using certain levels that the
organisms need to pass in order to go on to the next level. The bottom level is the domain and the
organism works its way up to the top level, which is species.
It is more useful for a microbiologist to use the Three Domain classification system because it classifies
organisms into smaller classifications rather than being broad. The Five Kingdom classification system is
more observation based while the Three Domain classification system is more DNA based.
,BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
Why must an electron microscope be used to see most viruses? Why can't they be seen using a light
microscope? - (ANSWER)An electron microscope must be used to see most viruses because viruses are
too small to be seen by the optical microscope. The electron microscope has a magnification of 5,000X
to 1,000,000X and it does not use light.
Viruses can't be seen using a light microscope because light microscopes do not have as much
magnification as the electron microscope and you will not be able to see the viruses.
What is the difference between a mixed culture and a pure culture of microbes? - (ANSWER)The
difference between a mixed culture and a pure culture of microbes is that a mixed culture are multiple
species growing in a container while a pure culture is one species growing in a container.
Mannitol Salt Agar and MacConkey Agar are two examples of media that is both selective and
differential. In your own words describe what selective and differential mean. - (ANSWER)Selective-
Contains one or more agents that restrain growth of a certain microbe(s) but urge the growth of
another.
Differential- Allows several types of microbes to grow and show differences among themselves.
All bacteria make humans ill. - (ANSWER)False
In the three domain classification system, all prokaryotic cells are grouped into Monera. -
(ANSWER)False
Angelina Hesse suggested adding ______ as a thickener to broth in order to make solid media. -
(ANSWER)Agar
Koch's postulates were used - (ANSWER)to definitively link one microorganism to one disease.
In this class of microorganisms, all members are prokaryotes. - (ANSWER)bacteria
,BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
The theory that states life can arise from nonliving things and would explain an infection by stating that
first the body would be in a diseased state after which microorganisms would appear is -
(ANSWER)spontaneous generation
How would you correctly abbreviate Helicobacter hepaticus? - (ANSWER)H. hepaticus
Which of the following class(es) of microorganisms can exist as a multicellular lifeform? (Select all that
apply.) - (ANSWER)Helminthes
Algae
Fungi
Which of the following classes of microorganisms are made up of eukaryotic cells? (Select all that apply.)
- (ANSWER)fungi
algae
helminthe
protozoa
Which of the following classes of microorganisms contain even one member that can make humans
sick? - (ANSWER)fungi
bacteria
viruses
protozoa
algae
helminthes
Bacteria are typically larger in size than viruses. - (ANSWER)true
Microbes are ubiquitous. - (ANSWER)true
What characteristics do all living organisms have? Do you agree that viruses are not living? Why or why
not? - (ANSWER)Characteristics that all living organisms have is; they are made of cells, they have a
, BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
metabolism, they have reproduction abilities, they are able to grow and develop, they are able to move,
and they have cell support, protection, and mechanisms.
I agree that viruses are not living, this is because they are not cells. One of the characteristics of being a
living organism is that they need to be made of cells.
How can fimbriae make a bacterial cell more virulent? How can a capsule make a bacterial cell more
virulent? - (ANSWER)We describe a pathogen (bacteria, viruses, etc.) as virulent when it is either better
able to infect and cause disease or cause more harm to the host due to factors such as presence of
fimbriae and capsules.
Fimbriae are short, hair-like structures that are attached to the cell membrane. They extend from the
cell and make the cell "sticky." The fimbriae allow the cell to attach to things such as the cells of your
body. Imagine two bacterial cells totally identical except for the fact that one contains fimbriae and the
other does not. If these two cells tried to infect your throat, the cell without fimbriae would quickly be
washed away (out of the body via a cough or sneeze, or into your stomach acid via the action of mucous
and cilia.) It would have little chance of causing an infection. The cell with fimbriae would be considered
more virulent because the fimbriae would allow it to attach to your cells and resist all of the body's
flushing mechanisms. It would be much more likely to cause an infection.
A bacterial capsule is a gel-like substance made of sugar and water that surrounds the outside of a
bacterial cell. The capsule is not antigenic meaning the host immune system doesn't recognize it as
something foreign that should be attacked. It also covers many of the things that are antigenic and
would spur the host immune system to attack (things like PTG, LPS, etc.) Imagine two bacterial cells,
identical except that one has a capsule and one does not. The one without a capsule would be quickly
identified and destroyed by the immune system. The one with a capsule would be more virulent
because it could evade detection (and destruction) by the host immune system.
What is a biofilm and where might you find one? - (ANSWER)A biofilm is a complex community of
microorganisms attached to a surface. A biofilm forms in pretty much any place that has microbes and
moisture. Two common places to find biofilms are on your teeth, and coating the insides of your
intestines. In a healthcare setting they can be problematic because they can form on prosthetic hips,
heart valves, catheters, etc.
There are two cell types - prokaryotic and eukaryotic. List the 7 classes or basic types of microorganisms
and identify each as prokaryotic, eukaryotic, both prokaryotic and eukaryotic, or neither. - (ANSWER)1.
Bacteria- prokaryotic
2. Archaea- prokaryotic
3. Algae- eukaryotic
4. Fungi- eukaryotic
5. Protozoa- eukaryotic
6. Helminthes- eukaryotic
7. Viruses- neither
What is a bacterial endospore? Explain how endospore-forming bacteria could cause a scientist to
believe in spontaneous generation. - (ANSWER)A bacterial endospore is an organism that is able to
survive in extreme conditions due to their tough structure.
Endospore-forming bacteria could cause scientists to believe in spontaneous generation because, they
can survive in extreme conditions that would normally kill bacteria. In spontaneous generation, it is said
that living things appear from vital forces existing in nonliving or decomposing matter, but there could
be bacterial endospore living in that situation without the scientists knowing.
Describe how organisms are placed in the Three Domain (Woese-Fox) classification system vs how
organisms are placed in the Five Kingdom (Traditional Wittaker) classification system. Which
classification system is more useful to a microbiologist and why? - (ANSWER)Organisms are placed in the
Three Domain classification system by using the three main branches, "Bacteria," Archaea," and
"Eukarya." They are placed in each domain based on what kind of cell they are (eukaryotic and
prokaryotic). Although prokaryotic cells are both Domain Bacteria and Domain Archaea, the members of
the Domain Archaea are very different from the ones in Domain Bacteria as they are able to live in
severe environments and are also able to produce metabolic byproducts.
Organisms are placed in the Five Kingdom classification system by using certain levels that the
organisms need to pass in order to go on to the next level. The bottom level is the domain and the
organism works its way up to the top level, which is species.
It is more useful for a microbiologist to use the Three Domain classification system because it classifies
organisms into smaller classifications rather than being broad. The Five Kingdom classification system is
more observation based while the Three Domain classification system is more DNA based.
,BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
Why must an electron microscope be used to see most viruses? Why can't they be seen using a light
microscope? - (ANSWER)An electron microscope must be used to see most viruses because viruses are
too small to be seen by the optical microscope. The electron microscope has a magnification of 5,000X
to 1,000,000X and it does not use light.
Viruses can't be seen using a light microscope because light microscopes do not have as much
magnification as the electron microscope and you will not be able to see the viruses.
What is the difference between a mixed culture and a pure culture of microbes? - (ANSWER)The
difference between a mixed culture and a pure culture of microbes is that a mixed culture are multiple
species growing in a container while a pure culture is one species growing in a container.
Mannitol Salt Agar and MacConkey Agar are two examples of media that is both selective and
differential. In your own words describe what selective and differential mean. - (ANSWER)Selective-
Contains one or more agents that restrain growth of a certain microbe(s) but urge the growth of
another.
Differential- Allows several types of microbes to grow and show differences among themselves.
All bacteria make humans ill. - (ANSWER)False
In the three domain classification system, all prokaryotic cells are grouped into Monera. -
(ANSWER)False
Angelina Hesse suggested adding ______ as a thickener to broth in order to make solid media. -
(ANSWER)Agar
Koch's postulates were used - (ANSWER)to definitively link one microorganism to one disease.
In this class of microorganisms, all members are prokaryotes. - (ANSWER)bacteria
,BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
The theory that states life can arise from nonliving things and would explain an infection by stating that
first the body would be in a diseased state after which microorganisms would appear is -
(ANSWER)spontaneous generation
How would you correctly abbreviate Helicobacter hepaticus? - (ANSWER)H. hepaticus
Which of the following class(es) of microorganisms can exist as a multicellular lifeform? (Select all that
apply.) - (ANSWER)Helminthes
Algae
Fungi
Which of the following classes of microorganisms are made up of eukaryotic cells? (Select all that apply.)
- (ANSWER)fungi
algae
helminthe
protozoa
Which of the following classes of microorganisms contain even one member that can make humans
sick? - (ANSWER)fungi
bacteria
viruses
protozoa
algae
helminthes
Bacteria are typically larger in size than viruses. - (ANSWER)true
Microbes are ubiquitous. - (ANSWER)true
What characteristics do all living organisms have? Do you agree that viruses are not living? Why or why
not? - (ANSWER)Characteristics that all living organisms have is; they are made of cells, they have a
, BIOL 203 Microbiology LCC Final Exam – Comprehensive Review & Study Guide
metabolism, they have reproduction abilities, they are able to grow and develop, they are able to move,
and they have cell support, protection, and mechanisms.
I agree that viruses are not living, this is because they are not cells. One of the characteristics of being a
living organism is that they need to be made of cells.
How can fimbriae make a bacterial cell more virulent? How can a capsule make a bacterial cell more
virulent? - (ANSWER)We describe a pathogen (bacteria, viruses, etc.) as virulent when it is either better
able to infect and cause disease or cause more harm to the host due to factors such as presence of
fimbriae and capsules.
Fimbriae are short, hair-like structures that are attached to the cell membrane. They extend from the
cell and make the cell "sticky." The fimbriae allow the cell to attach to things such as the cells of your
body. Imagine two bacterial cells totally identical except for the fact that one contains fimbriae and the
other does not. If these two cells tried to infect your throat, the cell without fimbriae would quickly be
washed away (out of the body via a cough or sneeze, or into your stomach acid via the action of mucous
and cilia.) It would have little chance of causing an infection. The cell with fimbriae would be considered
more virulent because the fimbriae would allow it to attach to your cells and resist all of the body's
flushing mechanisms. It would be much more likely to cause an infection.
A bacterial capsule is a gel-like substance made of sugar and water that surrounds the outside of a
bacterial cell. The capsule is not antigenic meaning the host immune system doesn't recognize it as
something foreign that should be attacked. It also covers many of the things that are antigenic and
would spur the host immune system to attack (things like PTG, LPS, etc.) Imagine two bacterial cells,
identical except that one has a capsule and one does not. The one without a capsule would be quickly
identified and destroyed by the immune system. The one with a capsule would be more virulent
because it could evade detection (and destruction) by the host immune system.
What is a biofilm and where might you find one? - (ANSWER)A biofilm is a complex community of
microorganisms attached to a surface. A biofilm forms in pretty much any place that has microbes and
moisture. Two common places to find biofilms are on your teeth, and coating the insides of your
intestines. In a healthcare setting they can be problematic because they can form on prosthetic hips,
heart valves, catheters, etc.
