BIOL 203 MICROBIOLOGY LCC
COMPREHENSIVE TEST BANK PRACTICE
QUESTIONS AND RATIONALES
●● 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.
●● 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
●● 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
COMPREHENSIVE TEST BANK PRACTICE
QUESTIONS AND RATIONALES
●● 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.
●● 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
●● 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
