Answer Options:
True
False
Answer: False
Question: True or False: The human skin is considered a more hostile environment for microbes than the human mouth.
Answer Options:
True
False
Answer: False
Question: Which of the following organisms is NOT likely to be found on the skin?
Answer Options:
Staphylococcus aureus
Micrococcus luteus
Propionibacterium granulosum
Staphylococcus epidermidis
Pseudomonas aeruginosa
Answer: Pseudomonas aeruginosa
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: What information does the Kirby-Bauer disk diffusion method provide?
Answer Options:
The mode of action of an antibiotic.
Types of allergic reactions a patient may exhibit.
An microbe’s sensitivity and resistance to antibiotics.
The origin of the antibiotic.
Answer: An microbe’s sensitivity and resistance to antibiotics.
Question: A total of 147 colonies were counted on the plate that received 1.0 mL of the 1:10,000 this could as be written as 10^-4 dilution of a specimen. What is the bacterial count for the original specimen?
Answer Options:
147,000,000 cfu/ml
14,700,000 cfu/ml
1,470,000 cfu/ml
147,000 cfu/ml
Answer: 1,470,000 cfu/ml
Question: Select the statement that best describes the purpose of gel electrophoresis.
Answer Options:
Gel electrophoresis enables the amplification of specific DNA sequences.
Gel electrophoresis runs different segments of DNA.
Gel electrophoresis is able to cut DNA in very specific locations.
Answer: Gel electrophoresis runs different segments of DNA.
Question: How are agar plates inoculated for disk diffusion testing of antimicrobial compounds?
Answer Options:
A swab is used to inoculate the entire surface of the plate, producing a lawn of growth.
A loop is used to prepare a 4-way quadrant streak.
A series of test dilutions is spread to achieve countable colonies.
A four-way quadrant streak is done using a swab.
Answer: A swab is immersed in a suspension of the microorganism and then used to inoculate.
Question: Bacterial enzymes that are used to cut DNA at specific nucleotide sequences are called _______ enzymes.
Answer Options:
polymerase
restriction
transcriptase
ligase
Answer: restriction
Question: Which of the following does the gene Bla encode for?
Answer Options:
green fluorescent protein, which glows.
beta-lactamase, which confers penicillin resistance.
Pribnow box, which is the promoter region for transcription of the operon.
araC, which is required for GFP transcription.
Answer: beta-lactamase, which confers penicillin resistance.
Question: At the beginning of each cycle of PCR, the temperature is raised to ~94 degrees C so that:
Answer Options:
Double-stranded DNA ‘melts’ open into single strands
All proteins may coagulate and take up the dye
To ensure DNA primers stick together
DNA primers extend along the templates
Answer: Double-stranded DNA ‘melts’ open into single strands
Question: The production or synthesis of proteins and carbohydrates by a bacterial cell is an example of:
Answer Options:
substrate-level phosphorylation
induction
catabolism
anabolism
fermentation
Answer: anabolism
Question: After acid-fast staining, “acid-fast” bacteria will be stained ___________.
Answer Options:
pink from fuchsin
purple from safranin
blue from methylene blue
pink from safranin
purple from crystal violet
Answer: pink from fuchsin
Question: During gel electrophoresis, larger DNA fragments migrate __________ through the agarose gel, compared to smaller DNA fragments.
Answer Options:
faster
slower
at the same speed
Answer: slower
Question: True or False: Interferons are effective against viral pathogens.
Answer Options:
True
False
Answer: True
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: When collecting bacteria to prepare a smear on a slide for staining, a general rule is “the more cells the better.”
Answer Options:
True
False
Answer: False
Question: In bacterial cells, the electron transport system is located in the:
Answer Options:
Cytoplasm
Cell membrane
Mitochondria
Chloroplast
Ribosome
Answer: Cell membrane
Question: Mannitol salt agar (MSA) is an example of a medium that is:
Answer Options:
Selective
Differential
Both
Answer: Both
Question: Which of the following is true about viruses in soil?
Answer Options:
They are present in low abundance.
They can be easily recovered from soil organic matter.
They can contribute to carbon cycling and organic matter degradation through auxiliary metabolic genes.
They allow the cells to withstand harsh environmental conditions.
Answer: They can contribute to carbon cycling and organic matter degradation through auxiliary metabolic genes.
Question: This type of culture most frequently used in the laboratory which contains only a single species of microbe.
Answer Options:
contaminated culture
pure culture
mixed culture
subculture
Answer: pure culture