MCB 2010C Microbiology 2025 Exam 2
Questions And Answers Graded A+
Which type of test is used to determine whether disinfectant solutions
actively used in a clinical setting are being used correctly?
in-use test
The effectiveness of chemical disinfectants has historically been
compared to that of which of the following?
phenol
Which of the following refers to a germicide that can kill vegetative
cells and certain enveloped viruses but not endospores?
low-level germicide
,Which of the following terms refers to the ability of an antimicrobial
drug to harm the target microbe without harming the host?
selective toxicity
Which of the following is not a type of β-lactam antimicrobial?
glycopeptides
A soup container was forgotten in the refrigerator and shows
contamination. The contaminants are probably which of the following?
psychrotrophs
Bacteria isolated from a hot tub at 39 °C are probably which of the
following?
mesophiles
In which environment are you most likely to encounter a
hyperthermophile?
hydrothermal vent at the bottom of the ocean
,Which of the following environments would harbor psychrophiles?
mountain lake with a water temperature of 12 °C
Which of the following methods would be used to measure the
concentration of bacterial contamination in processed peanut butter?
total plate count
In which phase would you expect to observe the most endospores in a
Bacillus cell culture?
death phase
During which phase would penicillin, an antibiotic that inhibits cell-wall
synthesis, be most effective?
log phase
Which of the following is the best definition of generation time in a
bacterium?
, the length of time it takes for a population of cells to double
What is the function of the Z ring in binary fission?
It forms a contractile ring at the septum.
If a culture starts with 50 cells, how many cells will be present after five
generations with no cell death?
1600
Quorum sensing is used by bacterial cells to determine which of the
following?
the density of the population
Which of the following statements about autoinducers is incorrect?
They bind directly to DNA to activate transcription. ( true: They can
activate the cell that secreted them, N-acylated homoserine lactones are
autoinducers in gram-negative cells, Autoinducers may stimulate the
production of virulence factors)
Questions And Answers Graded A+
Which type of test is used to determine whether disinfectant solutions
actively used in a clinical setting are being used correctly?
in-use test
The effectiveness of chemical disinfectants has historically been
compared to that of which of the following?
phenol
Which of the following refers to a germicide that can kill vegetative
cells and certain enveloped viruses but not endospores?
low-level germicide
,Which of the following terms refers to the ability of an antimicrobial
drug to harm the target microbe without harming the host?
selective toxicity
Which of the following is not a type of β-lactam antimicrobial?
glycopeptides
A soup container was forgotten in the refrigerator and shows
contamination. The contaminants are probably which of the following?
psychrotrophs
Bacteria isolated from a hot tub at 39 °C are probably which of the
following?
mesophiles
In which environment are you most likely to encounter a
hyperthermophile?
hydrothermal vent at the bottom of the ocean
,Which of the following environments would harbor psychrophiles?
mountain lake with a water temperature of 12 °C
Which of the following methods would be used to measure the
concentration of bacterial contamination in processed peanut butter?
total plate count
In which phase would you expect to observe the most endospores in a
Bacillus cell culture?
death phase
During which phase would penicillin, an antibiotic that inhibits cell-wall
synthesis, be most effective?
log phase
Which of the following is the best definition of generation time in a
bacterium?
, the length of time it takes for a population of cells to double
What is the function of the Z ring in binary fission?
It forms a contractile ring at the septum.
If a culture starts with 50 cells, how many cells will be present after five
generations with no cell death?
1600
Quorum sensing is used by bacterial cells to determine which of the
following?
the density of the population
Which of the following statements about autoinducers is incorrect?
They bind directly to DNA to activate transcription. ( true: They can
activate the cell that secreted them, N-acylated homoserine lactones are
autoinducers in gram-negative cells, Autoinducers may stimulate the
production of virulence factors)
