Question 1

Which of the following statements are true concerning chemically defined media? (Select all that apply)

Accepted Answer

A)   In chemically defined media all concentrations of every ingredient are known.
B)   Chemically defined media contain defined amounts of carbon and energy sources.
C)   In chemically defined media a buffer is used to maintain an appropriate pH.
D)   In a chemically defined media salts are added to maintain osmotic balance.E) C) and D)
F) B) and D)

Question 2

A(n)  ________ can only grow in anaerobic conditions.

Accepted Answer

A)   obligate aerobe
B)   facultative anaerobe
C)   aerotolerant anaerobe
D)   obligate anaerobeE) A) and D)
F) All of the above

Question 3

An example of a bacterial species that shows the growth pattern seen below is ________.

Accepted Answer

A)   Streptococcus pyogenes
B)   Streptococcus pneumoniae
C)   E. coli
D)   SalmonellaE) None of the above
F) B) and C)

Question 4

In a hypertonic environment, which way will water flow via osmosis?

Accepted Answer

A)   Into the cell
B)   Out of the cell
C)   Neither since movement of water particles in and out of the cell will be equal
D)   Neither because there will be no movement of water into or out of the cellE) A) and D)
F) A) and C)

Question 5

Microorganisms that obtain their energy from inorganic molecules and obtain the carbon they need to build macromolecules from CO2 are ________.

Accepted Answer

A)   photoheterotrophs
B)   photoautotrophs
C)   chemoheterotrophs
D)   chemoautotrophsE) B) and D)
F) A) and D)

Question 6

The illustration below depicts the growth of bacteria in nutrient agar tubes after stabbing an inoculum of bacteria through the center of the medium to the bottom of the tube. Tube "z" represents the growth of ________.

Accepted Answer

A)   obligate aerobes
B)   obligate anaerobes
C)   facultative anaerobes
D)   aerotolerant anaerobesE) A) and C)
F) B) and C)

Question 7

Which of the following methods of measuring cell density would be the best to choose when you know that you do not have a lot of bacteria present in your sample?

Accepted Answer

A)   A Petroff-Hausser chamber because you are visually counting bacteria.
B)   Spectrophotometry because it is sensitive to low bacterial numbers.
C)   Dilution plating because you will be able to count between 30-300 cells on a plate.
D)   Filtration because the number of bacteria may be concentrated on the filter prior to plating.E) A) and B)
F) A) and D)

Question 8

Characteristics of nonculture techniques include ________. (Select all that apply)

Accepted Answer

A)   completion of the assay occurs more rapidly that a cultural technique
B)   utilization of tests for antibodies that are produced as a result of infection, for microbial products or for microbial DNA or RNA
C)   antibody-based tests can include agglutination tests and direct fluorescent antibody assays
D)   ELISA tests are one type of antibody test that rely on easily seen color changesE) B) and D)
F) B) and C)

Question 9

Region 3 of the growth curve of bacteria shown in the illustration below depicts the ________ of growth.

Accepted Answer

A)   log phase
B)   stationary phase
C)   lag phase
D)   death phaseE) A) and B)
F) All of the above

Question 10

The illustration below depicts the growth of bacteria in nutrient agar tubes after stabbing an inoculum of bacteria through the center of the medium to the bottom of the tube. Tube "v" represents the growth of ________.

Accepted Answer

A)   obligate aerobes
B)   microaerophiles
C)   facultative anaerobes
D)   aerotolerant anaerobesE) A) and C)
F) None of the above

Question 11

Which of these is a correct match? (Select all that apply)

Accepted Answer

A)   Growth medium: an artificial liquid or gel containing nutrients designed to meet the microbes' specific growth requirements.
B)   Inoculum: a small sample of microorganisms which are placed into a growth medium to produce a culture.
C)   Colony: a visible mass of cells descended from a single cell.
D)   Pure culture: all the cells descended from single ancestor cell.E) A) and B)
F) All of the above

Question 12

Which of the following chemicals may be used to sterilize heat-sensitive material? (Select all that apply)

Accepted Answer

A)   95% alcohol gel.
B)   Formaldehyde preserves anatomical specimens.
C)   Ethylene oxide gas sterilizes materials that are both heat and moisture sensitive.
D)   Quaternary ammonium compounds.E) A) and D)
F) C) and D)

Question 13

Microorganisms that obtain their energy from light and obtain the carbon they need to build macromolecules from CO2 are ________.

Accepted Answer

A)   photoheterotrophs
B)   photoautotrophs
C)   chemoheterotrophs
D)   chemoautotrophsE) C) and D)
F) None of the above

Question 14

An example of a bacterial species that shows the growth pattern seen below is ________.

Accepted Answer

A)   Streptococcus pyogenes
B)   Streptococcus pneumoniae
C)   E. coli
D)   SalmonellaE) B) and C)
F) A) and D)

Question 15

Sterilization ________.

Accepted Answer

A)   is the reduction of infection risk on living tissue
B)   is using nontoxic chemicals used to inhibit growth of microbes on food
C)   is the destruction or removal of all microbes
D)   is the destruction or removal of microbes capable of infectionE) A) and B)
F) None of the above

Question 16

How can growth medium be classified? (Select all that apply)

Accepted Answer

A)   According to its physical properties.
B)   According to its chemical properties.
C)   As selective growth media.
D)   As differential growth media.E) A) and D)
F) A) and C)

Question 17

Optimum growth rate is above 80ᵒC for ________.

Accepted Answer

A)   psychrophiles
B)   mesophiles
C)   thermophiles
D)   hyperthermophilesE) A) and B)
F) B) and C)

Question 18

Pasteurization ________.

Accepted Answer

A)   is used to slow microbial metabolism and growth
B)   reduces the number of microbes so that there is less spoilage of consumable liquids
C)   breaks C-C bonds which denatures proteins and nucleic acids
D)   forces hot water vapor into endosporesE) All of the above
F) A) and C)

Question 19

The major characteristics of chemical control agents as a group include ________. (Select all that apply)

Accepted Answer

A)   they may be placed into 3 groups based on strength of control: sterilants, disinfectants and antiseptics
B)   their primary function is to kill, inactivate or inhibit growth of microbes
C)   they have different toxicities that govern their safe use
D)   some of these are so toxic that they must be used under strict supervision and/or restricted placesE) B) and D)
F) A) and D)

Question 20

A psychrophilehas an optimum growth rate ________.

Accepted Answer

A)   above 80ᵒC
B)   between 15 and 30ᵒC
C)   below 15ᵒC
D)   between 50ᵒC and 80ᵒCE) B) and C)
F) None of the above

Exam 11: Microbial Growth and Control

Sterilization ________.

Correct AnswerverifiedShow Answer

In a hypertonic environment, which way will water flow via osmosis?

Correct AnswerverifiedShow Answer

Microorganisms that obtain their energy from inorganic molecules and obtain the carbon they need to build macromolecules from CO2 are ________.

Correct AnswerverifiedShow Answer

Optimum growth rate is above 80ᵒC for ________.

Correct AnswerverifiedShow Answer

Region 3 of the growth curve of bacteria shown in the illustration below depicts the ________ of growth.

Correct AnswerverifiedShow Answer

Which of the following statements are true concerning chemically defined media? (Select all that apply)

Correct AnswerverifiedShow Answer

The illustration below depicts the growth of bacteria in nutrient agar tubes after stabbing an inoculum of bacteria through the center of the medium to the bottom of the tube. Tube "v" represents the growth of ________.

Correct AnswerverifiedShow Answer

The illustration below depicts the growth of bacteria in nutrient agar tubes after stabbing an inoculum of bacteria through the center of the medium to the bottom of the tube. Tube "z" represents the growth of ________.

Correct AnswerverifiedShow Answer

Which of the following chemicals may be used to sterilize heat-sensitive material? (Select all that apply)

Correct AnswerverifiedShow Answer

An example of a bacterial species that shows the growth pattern seen below is ________.

Correct AnswerverifiedShow Answer

Microorganisms that obtain their energy from light and obtain the carbon they need to build macromolecules from CO2 are ________.

Correct AnswerverifiedShow Answer

A(n) ________ can only grow in anaerobic conditions.

Correct AnswerverifiedShow Answer

Which of the following methods of measuring cell density would be the best to choose when you know that you do not have a lot of bacteria present in your sample?

Correct AnswerverifiedShow Answer

Pasteurization ________.

Correct AnswerverifiedShow Answer

Which of these is a correct match? (Select all that apply)

Correct AnswerverifiedShow Answer

Characteristics of nonculture techniques include ________. (Select all that apply)

Correct AnswerverifiedShow Answer

How can growth medium be classified? (Select all that apply)

Correct AnswerverifiedShow Answer

The major characteristics of chemical control agents as a group include ________. (Select all that apply)

Correct AnswerverifiedShow Answer

A psychrophilehas an optimum growth rate ________.

Correct AnswerverifiedShow Answer

An example of a bacterial species that shows the growth pattern seen below is ________.

Correct AnswerverifiedShow Answer

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Microorganisms that obtain their energy from inorganic molecules and obtain the carbon they need to build macromolecules from CO₂ are ________.

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Microorganisms that obtain their energy from light and obtain the carbon they need to build macromolecules from CO₂ are ________.

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