Question 1 Saved
Turbidity gives a measure of the viable bacteria in a culture.
Question 3 options:
True
False
Question 2

Saved
In the plaque assay, how do the plaques form in the bacterial lawn?
Question 4 options:
A bacterial cell infects and kills a bacteriophage. The bacteria release cytotoxic proteins that kill neighboring cells. This cycle repeats until a circular, clear zone is formed on the lawn
A bacterial cell infects and kills a bacteriophage. The bacteria migrate to a remote area with additional phages. The migrating bacteria leave clear zone without phages on the lawn
A bacteriophage infects and kills a bacterial cell. Phage progeny are released and then kill neighboring cells. This cycle repeats until a circular, clear zone is formed on the lawn.
A bacteriophage infects bacterial cells in the soft agar. The bacteria multiply at a faster rate than the normal log growth rate. This cycle repeats until a circular area of phage infected bacteria is growing rapidly on the lawn.
Question 3

Saved
What are PFUs?
Question 5 options:
Plaque forming units: the number of infective phage particles
Phage founding units: the quantity of phages needed for founding a plaque
Personal filming units: the units of bacteria need to create a lawn (or film) on the agar
Polyclonal framing units: the ability of the bacteriophage to bind to antibodies
Question 4

Saved
Bacterial growth refers to an increase in the numbers of cells in a bacterial culture.
Question 6 options:
True
False
Question 5

Saved
The table below show the absorbance values of a bacterial culture measured at different time points
Time (min) Absorbance
0 0.12
20 0.18
40 0.21
60 0.24
80 0.36
100 0.42
120 0.48
According to the data above, what is the doubling (generation) time for this culture?
Question 9 options:
10 min
20 min
40 min
60 min
120 min
Question 6

Saved
What would be the doubling time of the bacterium at that temperature?
Question 10 options:

Question 11 options:
They do not use oxygen.
They prefer less oxygen than what is present in the atmosphere.
They prefer to use oxygen, but can do without.
They cannot survive without oxygen
They are killed in the presence of oxygen
Question 12 (

Saved
Bacteria that prefer O2 but can live in anaerobic conditions belong to the group of
Question 12 options:
micraerophiles
obligate aerobes
aerotolerants
obligate anaerobes
facultative anaerobes
Question 13

Saved
Microaerophile
Question 13 options:
dependent on oxygen
doesn't use oxygen
will die in the presence of oxygen
can grow in the presence of oxygen (won't die) but doesn't use it
Uses a small amount of oxygen
Question 15

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A physician suspects a Pseudomonas infection is causing a lung infection. When grown in the laboratory, Ii will only grow at the top of a thioglycolate broth tube. Which of the following measures should be followed to insure the sample contains live bacteria when it reaches the lab?
Question 15 options:
Put the sample in an anaerobic packet for delivery
Make sure the shipping container allows oxygen to reach the bacteria
It doesn't matter what type of container you ship it in, it survives under any oxygen level
The container must only contain a narrow range of oxygen concenration.
Doesn't matter
Question 16

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Cytochrome oxidase is characteristic of anaerobic bacteria.
Question 16 options:
True
False
Question 17

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In stab cultures, aerobic bacteria grow in the bottom
Question 17 options:
True
False
Question 18

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Agar deeps are often used to grow aerobic bacteria that require oxygen to survive.
Question 18 options:
True
False
Question 19

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A physician suspects Clostridium infection in a gangrenous wound. In the lab, Clostridium grows at the bottom of a thrioglycolate broth tube. Which of the following measures should be followed to insure the sample contains live bacteria when it reaches the lab?
Question 19 options:
Swab the surface of the wound to collect the sample
Use anaerobic transport packet/media
Make sure the lid on the transport packet is loose to allow oxygen in
Put the sample in rich medium to insure no endospores are formed
It doesn't matter
Question 20

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For antibiotic testing Mueller Hinton agar is used because of its antimicrobial properties
Question 20 options:
True
False
Question 21

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Antibiotics are natural antibacterials
Question 21 options:
True
False
Question 22

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Please explain in one sentence: what is the difference between disinfectants and antiseptics?
Question 22 options:

Question 23

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Oxidizing agents include all of the following EXCEPT
Question 23 options:
ozone.
hydrogen peroxide.
chlorine.
iodine.
glutaraldehyde.
Question 24