Answer Options:
does not use heat
decolorizer is used
uses a secondary stain
uses a negative stain (staining of the background)
represents a differential stain
heat fixing adheres bacteria to slide
Answer: does not use heat
uses a secondary stain
uses a negative stain (staining of the background)
represents a differential stain
Question: What organism are viruses not capable of infecting?
Answer: Other viruses
Question: 4 serial dilutions of a bacterial culture are plated on 4 standard plates. Plate A contains 2 colonies, plate B has 19 colonies, plate C has 212 colonies, and plate D has 1857 colonies. Which plate provides the most reliable result to calculate the original cell concentration?
Answer Options:
D
C
A
B
Answer: C
Question: 56 colonies grow on a nutrient agar plate from 1.0 ml of sample spread from a solution diluted 1 to 1000 in a standard plate count procedure. How many cfu/ml were in the original sample?
Answer Options:
56,000
5,600
560
0.0056
Answer: 56 × 1000 = 56,000
Question: The goal of ____________ technique is to minimize the contamination of both original and newly inoculated cultures as well as to protect the laboratory worker from contamination.
Answer Options:
inoculation
antiseptic
isolation
aseptic
Answer: aseptic
Question: “Microbes are everywhere” is another way of saying that microbes are ___________.
Answer Options:
inoculating
aseptic
unbiotic
ubiquitous
undulating
Answer: ubiquitous
Question: You are a new member of the Micro Lab prep staff. In order to get the best media making assignments for the semester, Professor Waters sets up a simple test: You must calculate the number of cells that grow in a bacterial culture over the course of an 8 hour incubation period. Here’s what you know:
The culture was started with 68 cells.
The generation time of this organism is 30 minutes.
The incubation period is 8 hours.
What is the total number of cells in the culture at the end of the 8 hour incubation period?
Answer Options:
32,640 cells
4,462,944 cells
6,323,786,496 cells
16,320 cells
Answer: 6,323,786,496 cells
Question: Viruses in the ocean are:
Answer Options:
A. The most numerically abundant biological entities.
B. The second most abundant predators.
C. The second largest biomass.
D. All of the above.
E. Both A & C.
Answer: D. All of the above
Question: Which items can be discarded in a regular trash can? (Select all that apply)
Answer Options:
Used glass slides
Uncontaminated waste paper
Paper towels used to wipe up bacterial spills
Wrappers from swabs or from disposable pipettes
Answer: Uncontaminated waste paper
Wrappers from swabs or from disposable pipettes
Question: True or False: Viruses are part of the healthy human microbiome.
Answer Options:
True
False
Answer: True
Question: Which items can be discarded in a regular trash can? (Select all that apply)
Answer Options:
used glass slides
uncontaminated wax paper
paper towels used to wipe up bacterial spills
wrappers from swabs or from disposable pipettes
Answer: uncontaminated wax paper
wrappers from swabs or from disposable pipettes
Question: True or False: The human microbiome is considered a commensal relationship.
Answer Options:
True
False
Answer: True
Question: Which of the following may indicate that you have correctly transferred a particular organism from a pure culture broth to an agar slant? (Select all that apply)
Answer Options:
The slant shows no signs of bacterial growth.
The slant shows only one color of growth.
The slant shows colonies in three different colors.
Answer: The slant shows only one color of growth.
Question: The material which provides the nutrients for growth is called the ___________.
Answer Options:
contaminant
culture medium
inoculation
incubator
Answer: culture medium
Question: If you perform a Gram stain on a pure culture of bacteria and you observe purple, sausage-shaped cells at 1000X magnification, what terms would you use to describe the bacteria?
Answer Options:
Gram-positive cocci
Gram-negative rods
Gram-positive spiral
Gram-positive rods
Answer: Gram-positive rods
Question: Bobtail squid:
Acquire new symbionts every day
Expel 5% of their symbionts every morning at dawn
Expel 95% of their symbionts every day at dawn
Don’t have symbionts
Answer: Expel 95% of their symbionts every day at dawn
Question: Uptake of naked DNA by a bacterium is:
Conjugation
Transfection
Transduction
Transformation
Correct Answer
Transformation
Answer:
Question: Which of the following may indicate that you have correctly transferred a particular organism from a pure culture broth to an agar slant? (Select all that apply)
Answer Options:
The slant shows no signs of bacterial growth.
There are streaks visible on the surface of the slant.
Growth is only at the bottom where the agar is located.
Growth is on the lid.
Growth is wherever location is most convenient.
Answer: There are streaks visible on the surface of the slant.
Question: Using the data in the table below, please choose the most accurate test result of “Staphylococcus aureus with a zone of inhibition diameter of 22 around a Gentamicin disk”
Answer Options:
susceptible
intermediate
resistant
Answer: susceptible
Question: The lab technician is loading a DNA sample into the wells. What laboratory technique is being performed?
Answer Options:
gel electrophoresis
bacterial transformation
DNA replication
Western blot
Answer: gel electrophoresis
Question: What is the role of arabinose in the pGLO transformation procedure?
Answer Options:
It selects for nontransformed cells whereas ampicillin selects for transformed bacteria.
It is a repressing substrate that turns off the transcription of GFP.
It is a required nutrient for any bacteria to grow.
It is an inducing substrate that allows the transcription of the gene of interest.
Answer: It is an inducing substrate that allows the transcription of the gene of interest.
Question: The goal of ____________ technique is to minimize the contamination of both original and newly inoculated cultures as well as to protect the laboratory worker from contamination.
Answer Options:
inoculation
antiseptic
isolation
aseptic
Answer: aseptic