Answer Options:
no growth zone
zone of inhibition
dash zone
zone of resistance
Answer: zone of inhibition
Question: While preparing to spread plates for colony counting, you forgot to dilute the original sample and just plated from it directly. Which of the following would be a likely outcome?
Answer Options:
There would be too few colonies to count.
There would be contamination that would interfere with obtaining an accurate count.
No growth would be observed on the agar plate because the bacteria used up all the nutrients in the broth.
Growth on the agar plate would be too crowded with no isolated colonies.
You would get just the right amount of colonies between 30 and 300 on the plate.
Answer: Growth on the agar plate would be too crowded with no isolated colonies.
Question: Which of the following items should be disposed of in a biohazard bag? (Select all that apply)
Answer Options:
paper and plastic waste from sterile swabs, pipettes, and stacks of culture media
paper towels used to clean up a bacterial spill
glass culture tubes
gloves used while working with infectious microbes
used agar plates
Answer: paper towels used to clean up a bacterial spill
gloves used while working with infectious microbes
used agar plates
Question: The results of a standard plate count are reported in ____________.
Answer Options:
cells/ml
mg/ml (micrograms/ml)
CFU/ml (colony forming units/ml)
Answer: CFU/ml (colony forming units/ml)
Question: Which of the following are reasons for washing hands before and after lab activities? (Select all that apply)
Answer Options:
Hands may become contaminated with infectious bacteria during lab experiments.
Hands may be contaminated with irritating chemicals during experiments.
Hands may be a source of contamination of lab experiments.
Hands may become soiled during lab.
Answer: Hands may become contaminated with infectious bacteria during lab experiments.
Hands may be contaminated with irritating chemicals during experiments.
Hands may be a source of contamination of lab experiments.
Question: True or False: PCR amplifies a DNA template in a linear fashion, so that a new copy is made at every cycle of the process, for example: cycle 1 = 2 copies; cycle 2 = 3 copies; cycle 3 = 4 copies, etc.
Answer Options:
True
False
Answer: False
Question: When preparing pure cultures, dilution is necessary for _____________.
Answer Options:
reducing the number of inoculated organisms so that isolated colonies can develop.
preparing the melted agar for pour plating.
All of the choices are correct.
providing a hypotonic environment to enhance bacterial growth.
ensuring that the bacteria receive adequate nutrition during incubation.
Answer: reducing the number of inoculated organisms so that isolated colonies can develop.
Question: Which of the following infectious agents is least likely to be damaged by UV exposure?
Answer Options:
Protozoa
Viruses
Bacteria
Fungi
Prions
Answer: Prions
Question: True or False: Microbes do not cause and/or are not associated with cancers or tumor cells.
Answer Options:
True
False
Answer: False
Question: The phases of a typical bacterial growth curve, in order, are:
Answer Options:
I, II, III, IV
lag, stationary, exponential, death
lag, exponential, stationary, death
Answer: lag, exponential, stationary, death
Question: Which bacterial species is found on human skin as part of the normal flora?
Answer Options:
Escherichia coli
Enterococcus faecalis
Staphylococcus epidermidis
Bacillus subtilis
Answer: Staphylococcus epidermidis