With Complete Solutions
A bacterial culture maintained under complete anaerobic
conditions accidentally develops a leak allowing oxygen into the
chamber. However, the bacteria continue to grow. The bacteria
are most likely
A)thermophiles.
B)halophiles.
C)aerobic.
D)aerotolerant anaerobes.
E)microaerophilic. Correct Answer D)aerotolerant anaerobes.
A camper is using a water filter in order to safely drink from a
stream. The filter is only able to filter out organisms larger than
1 micron. From which of the following organisms would it most
likely protect people?
A)All bacteria and protozoa.
B)Almost all viruses and fungi.
C)All viruses and bacteria.
D)Some bacteria and almost all protozoa.
E)Only viruses. Correct Answer D)Some bacteria and almost
all protozoa.
A chemostat is used to
A)select for certain species of bacteria.
B)enrich the culture environment for certain species of bacteria.
C)maintain a bacterial culture in continuous exponential growth.
D)maintain bacterial cultures for future generations.
E)None of these choices are correct. Correct Answer
C)maintain a bacterial culture in continuous exponential growth.
,A fatty acid that contains numerous double bonds would be
called a(n) ___________ fat.
A)saturated
B)unsaturated
C)polyunsaturated
D)steroid
E)phospholipid Correct Answer C)polyunsaturated
A friend comments to you that all bacteria should be killed to
make the world safer. Which of the following would likely
result if such a scenario occurred?
A)Certain foods such as cheese could not be made easily.
B)Humans would have fewer fungal diseases.
C)No medicines could be manufactured.
D)Humans would be free of disease.
E)Plants would be free of disease. Correct Answer A)Certain
foods such as cheese could not be made easily.
A lipopolysaccharide molecule that is released from the outer
membrane of Gram-negative bacteria cell walls and causes the
symptoms of the bacterial infection is called:
A)porin
B)endotoxin
C)exotoxin
D)plasmid
E)peptidoglycan Correct Answer B)endotoxin
A method that counts only live microbes is the
A)pure culture method.
B)plate count method.
, C)cell counting method.
D)turbidity method.
E)None of these choices are correct. Correct Answer B)plate
count method.
A microorganism isolated from the Arctic region would most
likely be
A)a mesophile.
B)facultative.
C)a psychrophile.
D)extremophilic.
E)a psychrotroph. Correct Answer C)a psychrophile.
A microorganism that grows in the presence of oxygen when it
is available but can also grow without oxygen is
A)microaerophilic.
B)aerobic.
C)an aerotolerant anaerobe.
D)a facultative anaerobe.
E)None of these choices are correct. Correct Answer D)a
facultative anaerobe.
A process in which wine, beer, and milk are heated to destroy
microorganisms that cause spoilage and increase the shelf life of
these products is called
A)centrifugation.
B)sterilization.
C)pasteurization.
D)autoclaving.
E)polymerization. Correct Answer C)pasteurization.