Microbiology (Tortora 12th edition)
Chapter 6, 7, 10, 11, 12 test bank
(2025-2026)
Question and Answers
Expert Verified
(With A+ Grades Guarantee)
,If cells are grown in media containing amino acids DNA and proteins.
labeled with radioactive nitrogen (15N), most of the
radioactivity will be found in the cells
Which of the following elements is NOT correctly phosphorus used for production of carbohydrates
matched with its cellular function?
Pathogenic bacteria isolated from the respiratory or capnophiles that grow best in carbon dioxide incubators.
intestinal tracts of humans are
The biosafety level (BSL) for most introductory BSL-1.
microbiology laboratories is
The biosafety level (BSL) for a clinical microbiology BSL-3.
laboratory working with potentially airborne pathogens,
such as tuberculosis bacteria, is
A sample of milk is tested for its bacterial content in a 54,000 cells per milliliter.
plate count assay. A one-milliliter sample of the milk is
diluted in a 1:10 dilution series. One milliliter of the third
dilution tube is plated in a pour plate. After incubation,
the plate has 54 colonies, indicating that the original milk
sample contained
The addition of which of the following to a culture buffers
medium will neutralize acids?
Salts and sugars work to preserve foods by creating a hypertonic environment.
The term aerotolerant anaerobe refers to an organism does not use oxygen but tolerates it.
that
Which of the following is an advantage of the standard determines the number of viable cells
plate count?
Which of the following is an advantage of the direct requires no incubation time
microscopic count?
Most bacteria reproduce by binary fission.
Thirty-six colonies grew in nutrient agar from 1.0 ml of 36 per milliliter
undiluted sample in a standard plate count. How many
cells were in the original sample?
Most bacteria grow best at pH 7
Most fungi grow best at pH 5
, Consider a culture medium on which only gram-positive selective and differential medium.
organisms such as Staphylococcus aureus colonies can
grow due to an elevated NaCl level. A yellow halo
surrounds the growth, indicating the bacterium fermented
a sugar in the medium, decreasing the pH as a result
and changing the color of a pH indicator chemical. This
type of medium would be referred to as a(n)
A culture medium consisting of agar, peptone, and beef complex medium
heart is a
Which of the following pairs of microbe classification thermophile growth at 37C
terms and optimal growth temperatures is mismatched?
During which growth phase will gram-positive bacteria be log phase
most susceptible to penicillin?
Which of the following is the best definition of generation the length of time needed for a cell to divide
time?
Which of the following is NOT a direct method to metabolic activity
measure microbial growth?
Which group of microorganisms is most likely to spoil a facultative halophiles
freshwater trout preserved with salt?
Which of the following is an organic growth factor? vitamin B1
Which of the following is an example of a metabolic glucose consumption
activity that could be used to measure microbial growth?
An experiment began with 4 cells and ended with 128 5
cells. How many generations did the cells go through?
Three cells with generation times of 60 minutes are 96
inoculated into a culture medium. How many cells are
there after 5 hours?
In one hospital, Pseudomonas aeruginosa serotype 10 a biofilm in the reprocessor
infected the biliary tract of 10 percent of 1300 patients
who underwent gastrointestinal endoscopic procedures.
After each use, endoscopes were washed with an
automatic reprocessor that flushed detergent and
glutaraldehyde through the endoscopes, followed by a
tap water rinse. P. aeruginosa serotype 10 was not
isolated from the detergent, glutaraldehyde, or tap water.
What was the source of the infections?
Assume you inoculated 100 cells, with a generation time the same number of cells in both.
of 20 minutes, into 100 ml of nutrient broth. You then
inoculated 100 cells of the same species into 200 ml of
nutrient broth. After incubation for 4 hours, you can
reasonably expect to have
The source of nutrients in nutrient agar is peptone and beef extract.
Chapter 6, 7, 10, 11, 12 test bank
(2025-2026)
Question and Answers
Expert Verified
(With A+ Grades Guarantee)
,If cells are grown in media containing amino acids DNA and proteins.
labeled with radioactive nitrogen (15N), most of the
radioactivity will be found in the cells
Which of the following elements is NOT correctly phosphorus used for production of carbohydrates
matched with its cellular function?
Pathogenic bacteria isolated from the respiratory or capnophiles that grow best in carbon dioxide incubators.
intestinal tracts of humans are
The biosafety level (BSL) for most introductory BSL-1.
microbiology laboratories is
The biosafety level (BSL) for a clinical microbiology BSL-3.
laboratory working with potentially airborne pathogens,
such as tuberculosis bacteria, is
A sample of milk is tested for its bacterial content in a 54,000 cells per milliliter.
plate count assay. A one-milliliter sample of the milk is
diluted in a 1:10 dilution series. One milliliter of the third
dilution tube is plated in a pour plate. After incubation,
the plate has 54 colonies, indicating that the original milk
sample contained
The addition of which of the following to a culture buffers
medium will neutralize acids?
Salts and sugars work to preserve foods by creating a hypertonic environment.
The term aerotolerant anaerobe refers to an organism does not use oxygen but tolerates it.
that
Which of the following is an advantage of the standard determines the number of viable cells
plate count?
Which of the following is an advantage of the direct requires no incubation time
microscopic count?
Most bacteria reproduce by binary fission.
Thirty-six colonies grew in nutrient agar from 1.0 ml of 36 per milliliter
undiluted sample in a standard plate count. How many
cells were in the original sample?
Most bacteria grow best at pH 7
Most fungi grow best at pH 5
, Consider a culture medium on which only gram-positive selective and differential medium.
organisms such as Staphylococcus aureus colonies can
grow due to an elevated NaCl level. A yellow halo
surrounds the growth, indicating the bacterium fermented
a sugar in the medium, decreasing the pH as a result
and changing the color of a pH indicator chemical. This
type of medium would be referred to as a(n)
A culture medium consisting of agar, peptone, and beef complex medium
heart is a
Which of the following pairs of microbe classification thermophile growth at 37C
terms and optimal growth temperatures is mismatched?
During which growth phase will gram-positive bacteria be log phase
most susceptible to penicillin?
Which of the following is the best definition of generation the length of time needed for a cell to divide
time?
Which of the following is NOT a direct method to metabolic activity
measure microbial growth?
Which group of microorganisms is most likely to spoil a facultative halophiles
freshwater trout preserved with salt?
Which of the following is an organic growth factor? vitamin B1
Which of the following is an example of a metabolic glucose consumption
activity that could be used to measure microbial growth?
An experiment began with 4 cells and ended with 128 5
cells. How many generations did the cells go through?
Three cells with generation times of 60 minutes are 96
inoculated into a culture medium. How many cells are
there after 5 hours?
In one hospital, Pseudomonas aeruginosa serotype 10 a biofilm in the reprocessor
infected the biliary tract of 10 percent of 1300 patients
who underwent gastrointestinal endoscopic procedures.
After each use, endoscopes were washed with an
automatic reprocessor that flushed detergent and
glutaraldehyde through the endoscopes, followed by a
tap water rinse. P. aeruginosa serotype 10 was not
isolated from the detergent, glutaraldehyde, or tap water.
What was the source of the infections?
Assume you inoculated 100 cells, with a generation time the same number of cells in both.
of 20 minutes, into 100 ml of nutrient broth. You then
inoculated 100 cells of the same species into 200 ml of
nutrient broth. After incubation for 4 hours, you can
reasonably expect to have
The source of nutrients in nutrient agar is peptone and beef extract.
