Microbiology UTA 2460 - Lab Practical 2
Exam UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS
What is the role of resazurin in fluid thioglycolate medium... - CORRECT
ANSWER Resazurin indicates the presence of oxygen in the media
A bacterial isolate is subcultured to two blood agar plates, one of which is incubated in an
anaerobe jar, and the other is incubated on a shelf in the incubator. After incubation, growth is
observed on the plate from the anaerobe jar, but there is not growth on the plate incubated on
the incubator shelf. Based on these results how would this organism be categorized... -
CORRECT ANSWER obligate anaerobe
Where would you predict an facultative anaerobe would grow in a tube of fluid thioglycolate
medium... - CORRECT ANSWER throughout the tube
The pink color in the top of the broth in an FTM tube indicates... - CORRECT
ANSWER the presence of oxygen
Both human pathogens and normal microbiota are typically classified as... - CORRECT
ANSWER mesophiles
Taq polymersae is a DNA polymerase enzyme that demonstrates maximal activity at 72C.
The organism from which this enzyme was isolated would most likely be classified as a... -
CORRECT ANSWER thermophile
Vibrio cholerae is the bacterium responsible for cholera, a GI tract infection. Normally, it
takes the ingestion of over one million bacterial cells to cause infection, but the consumption
of antacids significantly lowers this number. What does this tell you about the likely
classification of V. cholerae in terms of pH preference... - CORRECT ANSWER it is
likely an alkaliphile
, How does pH negatively affect the metabolism of microorganisms... - CORRECT
ANSWER pH changes can denature enzymes
Why can jams and honey be stored at room temperature for long periods of time... -
CORRECT ANSWER the high sugar content causes plasmolysis of bacterial cells
Microorganisms that can grow at salt concentrations as high as 15-30% are known as... -
CORRECT ANSWER halophiles
An experiment involves the inoculation bacteria onto a variety of media with NaCl
concentrations ranging from 1% to 25%. Which of these media is most likely to be isotonic
with the bacterial cells... - CORRECT ANSWER 1%
Which of the following would be appropriately sterilized using UV radiation... - CORRECT
ANSWER stainless steel surface in biological safety cabinet used for media
preparation
Which of the following infectious agents is least likely to be damaged by UV exposure... -
CORRECT ANSWER prions
When two adjacent thymine molecules are joined by a covalent bond as a result of exposure
to UV light, this structure is referred to as a... - CORRECT ANSWER thymine dimer
How are agar plats inoculated for disk diffusion testing of antiseptics and disinfectants... -
CORRECT ANSWER a swab is used to inoculate the entire surface of the plate,
producing a lawn of growth
How is an antiseptic different from a disinfectant... - CORRECT ANSWER an
antiseptic is used to remove to kill microorganisms on tissue, whereas a disinfectant is used to
remove or kill microorganisms on inanimate objects
Exam UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS
What is the role of resazurin in fluid thioglycolate medium... - CORRECT
ANSWER Resazurin indicates the presence of oxygen in the media
A bacterial isolate is subcultured to two blood agar plates, one of which is incubated in an
anaerobe jar, and the other is incubated on a shelf in the incubator. After incubation, growth is
observed on the plate from the anaerobe jar, but there is not growth on the plate incubated on
the incubator shelf. Based on these results how would this organism be categorized... -
CORRECT ANSWER obligate anaerobe
Where would you predict an facultative anaerobe would grow in a tube of fluid thioglycolate
medium... - CORRECT ANSWER throughout the tube
The pink color in the top of the broth in an FTM tube indicates... - CORRECT
ANSWER the presence of oxygen
Both human pathogens and normal microbiota are typically classified as... - CORRECT
ANSWER mesophiles
Taq polymersae is a DNA polymerase enzyme that demonstrates maximal activity at 72C.
The organism from which this enzyme was isolated would most likely be classified as a... -
CORRECT ANSWER thermophile
Vibrio cholerae is the bacterium responsible for cholera, a GI tract infection. Normally, it
takes the ingestion of over one million bacterial cells to cause infection, but the consumption
of antacids significantly lowers this number. What does this tell you about the likely
classification of V. cholerae in terms of pH preference... - CORRECT ANSWER it is
likely an alkaliphile
, How does pH negatively affect the metabolism of microorganisms... - CORRECT
ANSWER pH changes can denature enzymes
Why can jams and honey be stored at room temperature for long periods of time... -
CORRECT ANSWER the high sugar content causes plasmolysis of bacterial cells
Microorganisms that can grow at salt concentrations as high as 15-30% are known as... -
CORRECT ANSWER halophiles
An experiment involves the inoculation bacteria onto a variety of media with NaCl
concentrations ranging from 1% to 25%. Which of these media is most likely to be isotonic
with the bacterial cells... - CORRECT ANSWER 1%
Which of the following would be appropriately sterilized using UV radiation... - CORRECT
ANSWER stainless steel surface in biological safety cabinet used for media
preparation
Which of the following infectious agents is least likely to be damaged by UV exposure... -
CORRECT ANSWER prions
When two adjacent thymine molecules are joined by a covalent bond as a result of exposure
to UV light, this structure is referred to as a... - CORRECT ANSWER thymine dimer
How are agar plats inoculated for disk diffusion testing of antiseptics and disinfectants... -
CORRECT ANSWER a swab is used to inoculate the entire surface of the plate,
producing a lawn of growth
How is an antiseptic different from a disinfectant... - CORRECT ANSWER an
antiseptic is used to remove to kill microorganisms on tissue, whereas a disinfectant is used to
remove or kill microorganisms on inanimate objects
