test 3 Flashcards
The MUG reagent is cleaved by what to yield a fluorescent compound?
a. heat
b. E. coli
O157:H7
c. glucuronidase
d. X-‐Glu
e. sugar
c. glucuronidase
Using a combination of the chromogenic compounds X-‐Glu and Rose-‐Gal enables the differentiation between:
a. coliforms and non-‐coliforms
b. E.coli and Salmonella
c. E. coli and other coliforms
d. Gram positive and Gram negative bacteria
e. nothing, as these are selective agents
c. E. coli and other coliforms
Spiral plating enables coverage of about how many 10-fold serial dilutions on a single plate?
a. 1, same as standard plating
b. none, it is used for producing confluent growth (lawn) of bacteria on the surface
c. 3 to 4
d. 10-‐1 to 10-‐2
e. 5 or more
c. 3 to 4
The direct microscopic count is commonly used to assess the quality of what food product?
a. raw milk
b. ground beef
c. processing water
d. pasteurized milk
e. cheese curds
a. raw milk
The inability of a bacterial sample to form colonies on a selective medium after exposure to a stressful situation is known as:
a. cell death
b. non-‐viable
c. sublethal injury
d. metabolic homeostasis
e. non-‐culturable situation
c. sublethal injury
Which of the following is an example of end product formation that would enable determination of microbial growth?
a. plasmid production
b. bubbles
c. separation of double-stranded DNA to single-stranded DNA
d. mitochondria
e. cleavage of MUG
b. bubbles
The addition of pyruvate to culture media can improve what?
a. detection of acid producers
b. conversion of pyruvate to acetyl-‐CoA
c. fluorescence of 4-‐methylumelliferone
d. anaerobic conditions
e. recovery of injured cells
e. recovery of injured cells
These enzymes cut DNA molecules between specific recognized nucleotide sequences.
a. restriction endonucleases
b. DNA ligases
c. DNA polymerases
d. deoxyribonucleases
e. DNA recombinases
a. restriction endonucleases
This statistically based method of estimating microbial populations utilizes 10-fold dilutions of a sample inoculated into broth media, and enables visual assessment of microbial growth that translate into estimated counts.
a. impedance
b. most probable number
c. dye reduction
d. bioluminescence
e. pressure detection
b. most probable number
The API 20E miniaturized diagnostic test is used to identify:
a. yeasts
b. shiga-‐toxin production E.coli
c. Enterobacteriaceae
d. lactic acid bacteria
e. Gram-‐positive cocci
c. Enterobacteriaceae
Restriction enzymes used in molecular biology procedures, such as pulse field gel electrophoresis, are obtained from:
a. decayed vegetable matter
b. mitochondria
c. recombinant DNA
d. bacteria
e. enzyme linked immunosorbent assays
d. bacteria
The “double antibody sandwich” ELISA utilizes two antibodies to detect a target organism – the capture antibody that is coated to microtiter plate wells and the _________ antibody that binds to the capture antibody-bound target organism.
a. enzyme
b. sandwich
c. fluorescent
d. horse radish peroxidase
e. reporter
e. reporter
This technique is used to separate DNA molecules through a gel matrix by applying an electric field that periodically changes directions?
a. impedance
b. gel electrophoresis
c. serpentation
d. PFGE
e. sievation
d. PFGE
Immunomagnetic separation enables the detection of target organisms based upon:
a. charge
b. polarity
c. specificity of antibodies
d. Gram reaction
e. the presence of iron in target organisms
c. specificity of antibodies
Bacteria produce restriction endonucleases as a mechanism for protection against invasion by foreign DNA, and protect their own DNA from restriction by what
process?
a. competitive exclusion
b. methylation
c. hydrogen bonding
d. phosphorylation
e. ligation
b. methylation
HindIII, the first discovered restriction endonuclease, was isolated from:
a. Haemophilus influenzae
b. geysers in Yellowstone National Park
c. the hind quarter of a pig
d. a bacteriophage
e. Kary Mullis
a. Haemophilus influenzae
In order for the polymerase chain reaction to work, the reaction mixture needs to contain the target DNA sequence, DNA polymerase, dNTPs, and what?
a. DNA probe
b. restriction endonuclease
c. methylated phosphates
d. forward and reverse primers
e. agarose gel
d. forward and reverse primers
Using gel electrophoresis, DNA fragments move through the gel towards the:
a. restriction endonuclease
b. negative terminal
c. positive terminal
d. appropriate antibody
e. south pole
c. positive terminal
Who discovered the polymerase chain reaction?
a. Louis Pasteur
b. Kary Mullis
c. Polly M. Euraseur
d. Edith Bunker
e. Gregor Mendel
b. Kary Mullis
During PCR, the denaturation step occurs at approximately what temperature?
a. 95°C
b. 25°C
c. 75°C
d. 37°C
e. 55°C
a. 95°C
During PCR, the renaturation step occurs at approximately what temperature?
a. 25°C
b. 55°C
c. 37°C
d. 75°C
e. 95°C
b. 55°C
During PCR, the synthesis step occurs at approximately what temperature?
a. 25°C
b. 37°C
c. 75°C
d. 55°C
e. 95°C
c. 75°C
After cycle 3 of the polymerase chain reaction, the amount of target DNA in each subsequent cycle is:
a. increased 10-‐fold
b. serially increased
c. halved
d. doubled
e. increased 100-‐fold
d. doubled
Thanks to the discovery of what, it is not required to add DNA polymerase at the end of each cycle of the polymerase chain reaction?
a. DNA ligase
b. dNTPs
c. reverse transcriptase
d. polygalactol catechin
e. Taq polymerase
e. Taq polymerase
What fluorescent dye binds indiscriminately to double stranded DNA?
a. Neutral Red
b. Indigo Blue
c. RETRO Sage
d. SYBR Green
e. AUTO blue
d. SYBR Green
Use of this type of PCR format incorporates a fluorescent dye and quencher in close proximity that eliminates fluorescence in the absence of DNA amplification.
a. dye chemistry
b. real-time PCR
c. TaqMan probes
d. RT-PCR
e. auxotrophic PCR
c. TaqMan probes
Performing the polymerase chain reaction assay after beginning with RNA requires what additional reagent to the PCR mix?
a. fluorescein
b. reverse transcriptase
c. RNA polymerase
d. messenger RNA
e. cDNA
b. reverse transcriptase
Traditional PCR can be used to detect the presence of viable bacteria in a sample by the use of what reagent added to the PCR mix?
a. ethidium bromide monoazide
b. catechin
c. polyhyaluronic diaminazole
d. acetylsalicylic acid
e. lysergic acid diethylamide
a. ethidium bromide monoazide
