Question 1

In a MALDI-TOF assay,

Accepted Answer

A)   antibodies are used to detect specific proteins and polysaccharides, particularly those that make up surface structures.
B)   a microorganism's proteins are separated and sorted by mass to generate a profile that provides a fast way to identify a colony.
C)   part of a colony is transferred to a microscope slide, and a drop of hydrogen peroxide (H2O2)  is added to it to test for catalase.
D)   specimens are inoculated onto differential media and a set of biochemical tests are used to identify a microorganism.
E)   the nucleotide sequence of ribosomal RNA molecules (rRNAs) , or the DNA that encodes them (rDNAs) , is used to identify microbes.F) B) and E)
G) A) and D)

Question 2

You have identified the causative organism of the outbreak as E. coli. In an effort to characterize the strain of the organism involved, you do different tests. The results are as follows:
Gram stain-Gram-negative rods; Oxidase test-negative; Lactose fermentation-positive; Serological testing-O157:H7; Colony morphology-smooth, creamy colonies; RFLPs-E. coli O157:H7; Antibiogram-resistant to ampicillin.
Which test(s)  confirm the identity of the organism at the strain level?

Accepted Answer

A)   Gram stain AND antibiogram
B)   Serological testing AND colony morphology
C)   RFLPs AND serological testing
D)   Oxidase test AND RFLPs
E)   Lactose fermentation AND oxidase testF) None of the above
G) All of the above

Question 3

Very often clinically relevant information may be obtained by examining

Accepted Answer

A)   a wet mount.
B)   the size and shape of the organism.
C)   the sequence of proteins.
D)   the transformation ability.
E)   a wet mount AND the size and shape of the organism.F) A) and B)
G) C) and D)

Question 4

Explain the difference between a biotype and a serotype.

Accepted Answer

A)   A biotype is the living type of microorganism identified, while the serotype is an individual's type of blood serum.
B)   A biotype is the type of biological environment a microbe will grow in, while the serotype is the type of blood serum that the microbe can grow in.
C)   A biotype is the particular phenotypic traits and characteristic structures of a biological microorganism, while the serotype is the list of molecules the microbe is able to make and secrete into the serum of an infected individual.
D)   A biotype is the biochemical profile of a particular microorganism, while the serotype is the difference in its surface structures/antigens that will lead to separate immune responses from an organism (characterized by presence of different antibodies in the individual's serum) .
E)   There is no real difference between a biotype and a serotype. These two words mean essentially the same thing and can be used interchangeably.F) A) and B)
G) A) and C)

Question 5

Modern approaches to evolutionary taxonomy often involve

Accepted Answer

A)   biochemical differences.
B)   comparison of DNA or RNA.
C)   protein similarities.
D)   lactose fermentation abilities.
E)   staining techniques.F) B) and E)
G) D) and E)

Question 6

You isolate a prokaryote. After performing analysis on the organism, you cannot find a description matching that of your organism in the reference text Bergey's Manual of Systematic Bacteriology. This suggests that you have likely isolated a new organism.

Accepted Answer

A) True 
 B)False

Question 7

Serological methods

Accepted Answer

A)   are useful in identifying bacteria.
B)   rely on the specificity of an antibody-antibody interaction.
C)   may be simple but are always time consuming.
D)   can rarely be used to identify bacteria.
E)   All of the answer choices are correct.F) A) and D)
G) A) and B)

Question 8

Gram-positive encapsulated diplococci found in sputum are likely

Accepted Answer

A)   Escherichia coli.
B)   Pseudomonas aeruginosa.
C)   Streptococcus pneumoniae.
D)   Neisseria gonorrhea.
E)   Bacillus cereus.F) None of the above
G) A) and C)

Question 9

E. coli is a Gram-negative bacillus that is found as intestinal normal microbiota. Which of the following would not be useful for an initial step in identifying E. coli O157:H7 strains in a stool sample?

Accepted Answer

A)   Gram staining, because E. coli strains will appear identical using this approach.
B)   Serology, because E. coli strains all express the same antigens.
C)   Growth on selective media, because all strains of E. coli will have the same metabolic capabilities.
D)   RFLPs, because E. coli strains will be identical at the genome level.
E)   These methods can all be used to differentiate between E. coli strains.F) None of the above
G) All of the above

Question 10

All known species of bacteria are described in Bergey's Manual of Systematic Bacteriology.

Accepted Answer

A) True 
 B)False

Question 11

Streptococcus pyogenes can be easily distinguished microscopically from other Streptococcus species.

Accepted Answer

A) True 
 B)False

Question 12

You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates

Accepted Answer

A)   the organisms are likely the same strain but you need to confirm this with other methods.
B)   the organisms are likely different strains but you need to confirm this with other methods.
C)   the two organisms are not likely to be susceptible to the same bacteriophages.
D)   the two organisms will show different results if they are Gram stained.
E)   the organisms are the same strains but they will react differently in serology tests.F) B) and E)
G) A) and C)

Question 13

Media that change color as a result of the biochemical activity of growing bacteria

Accepted Answer

A)   usually contain a pH indicator.
B)   usually contain blood.
C)   usually require the addition of various reagents before the color is evident.
D)   contain a colorless reagent that breaks down.
E)   are always selective media.F) B) and D)
G) All of the above

Question 14

Which of the following is NOT a method used to differentiate E. coli O157:H7 from other strains based directly on genotype?

Accepted Answer

A)   Fluorescence in situ hybridization (FISH) 
B)   Nucleic acid amplification tests (NAATs) 
C)   Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) 
D)   16S rRNA gene sequencing
E)   Radioisotope-labeled probes or fluorescent dye-labeled probesF) A) and B)
G) A) and C)

Question 15

The three domain classification scheme uses

Accepted Answer

A)   order, phylum, class.
B)   Archaea, Bacteria, Eukarya.
C)   Plants, Animals, Bacteria.
D)   Protista, Prokaryotae, Fungi.
E)   Bacteria, Archaea, AnimaliaF) C) and D)
G) B) and E)

Question 16

Please select the FALSE statement regarding taxonomic hierarchy.

Accepted Answer

A)   A species is a group of closely related strains or an organism; it is the basic unit of taxonomy.
B)   A genus is a collection of related species.
C)   A phylum is a collection of similar classes; it may also be called a division.
D)   A domain is a collection of similar kingdoms; there are three domains: Bacteria, Archaea, and Animalia.
E)   A kingdom is a group of several phyla or divisions; a collection of similar kingdoms makes up a domain.F) B) and D)
G) C) and D)

Question 17

You tell the patient that his sample contains white blood cells in which Gram-negative diplococci can be detected. Your patient asks how you obtained this result and you tell him you

Accepted Answer

A)   performed a Gram stain.
B)   performed an acid-fast stain.
C)   cultured his discharge on Gram-positive medium.
D)   cultured his discharge on Gram-negative medium.
E)   performed an antibiogram.F) A) and B)
G) A) and C)

Question 18

The three domain systems consist of Archaea, Bacteria, and Eukarya.

Accepted Answer

A) True 
 B)False

Question 19

Which statement regarding the Gram stain is FALSE?

Accepted Answer

A)   A Gram stain may give sufficient information to start appropriate antibiotic treatment-for example a Gram-positive diplococcus in sputum is likely to be Streptococcus pneumoniae.
B)   A Gram stain can sometimes be used to make a diagnosis-for example a Gram-negative diplococcus in WBC from urethral discharge is Neisseria gonorrhoeae.
C)   Gram staining can be used to differentiate intestinal normal microbiota from pathogens-for example differentiating E. coli from Salmonella enterica.
D)   In most cases, Gram staining is not sufficient to identify an organism-for example, Gram-positive staphylococci on skin may be either S. aureus or S. epidermidis.
E)   Medically important bacteria can seldom be identified by Gram staining alone-for example the throat may harbor Streptococcus pyogenes (pathogen)  as well as Streptococcus species that are normal microbiota.F) A) and B)
G) A) and C)

Question 20

To study the phylogeny of eukaryotes,

Accepted Answer

A)   16S rRNA is used.
B)   18S rRNA is used.
C)   40S rRNA is used.
D)   80S rRNA is used.
E)   70S rRNA is used.F) B) and C)
G) A) and D)

Exam 10: Identifying and Classifying Microorganisms

You isolate a prokaryote. After performing analysis on the organism, you cannot find a description matching that of your organism in the reference text Bergey's Manual of Systematic Bacteriology. This suggests that you have likely isolated a new organism.

Correct Answer
verified

Modern approaches to evolutionary taxonomy often involve

Correct Answer
verified

Serological methods

Correct Answer
verified

The three domain classification scheme uses

Correct Answer
verified

In a MALDI-TOF assay,

Correct Answer
verified

Gram-positive encapsulated diplococci found in sputum are likely

Correct Answer
verified

Very often clinically relevant information may be obtained by examining

Correct Answer
verified

All known species of bacteria are described in Bergey's Manual of Systematic Bacteriology.

Correct Answer
verified

To study the phylogeny of eukaryotes,

Correct Answer
verified

E. coli is a Gram-negative bacillus that is found as intestinal normal microbiota. Which of the following would not be useful for an initial step in identifying E. coli O157:H7 strains in a stool sample?

Correct Answer
verified

Media that change color as a result of the biochemical activity of growing bacteria

Correct Answer
verified

You tell the patient that his sample contains white blood cells in which Gram-negative diplococci can be detected. Your patient asks how you obtained this result and you tell him you

Correct Answer
verified

Correct Answer
verified

Which of the following is NOT a method used to differentiate E. coli O157:H7 from other strains based directly on genotype?

Correct Answer
verified

Explain the difference between a biotype and a serotype.

Correct Answer
verified

Streptococcus pyogenes can be easily distinguished microscopically from other Streptococcus species.

Correct Answer
verified

Which statement regarding the Gram stain is FALSE?

Correct Answer
verified

The three domain systems consist of Archaea, Bacteria, and Eukarya.

Correct Answer
verified

Please select the FALSE statement regarding taxonomic hierarchy.

Correct Answer
verified

You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates

Correct Answer
verified

Exam 10: Identifying and Classifying Microorganisms

You isolate a prokaryote. After performing analysis on the organism, you cannot find a description matching that of your organism in the reference text Bergey's Manual of Systematic Bacteriology. This suggests that you have likely isolated a new organism.

Correct AnswerverifiedShow Answer

Modern approaches to evolutionary taxonomy often involve

Correct AnswerverifiedShow Answer

Serological methods

Correct AnswerverifiedShow Answer

The three domain classification scheme uses

Correct AnswerverifiedShow Answer

In a MALDI-TOF assay,

Correct AnswerverifiedShow Answer

Gram-positive encapsulated diplococci found in sputum are likely

Correct AnswerverifiedShow Answer

Very often clinically relevant information may be obtained by examining

Correct AnswerverifiedShow Answer

All known species of bacteria are described in Bergey's Manual of Systematic Bacteriology.

Correct AnswerverifiedShow Answer

To study the phylogeny of eukaryotes,

Correct AnswerverifiedShow Answer

E. coli is a Gram-negative bacillus that is found as intestinal normal microbiota. Which of the following would not be useful for an initial step in identifying E. coli O157:H7 strains in a stool sample?

Correct AnswerverifiedShow Answer

Media that change color as a result of the biochemical activity of growing bacteria

Correct AnswerverifiedShow Answer

You tell the patient that his sample contains white blood cells in which Gram-negative diplococci can be detected. Your patient asks how you obtained this result and you tell him you

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following is NOT a method used to differentiate E. coli O157:H7 from other strains based directly on genotype?

Correct AnswerverifiedShow Answer

Explain the difference between a biotype and a serotype.

Correct AnswerverifiedShow Answer

Streptococcus pyogenes can be easily distinguished microscopically from other Streptococcus species.

Correct AnswerverifiedShow Answer

Which statement regarding the Gram stain is FALSE?

Correct AnswerverifiedShow Answer

The three domain systems consist of Archaea, Bacteria, and Eukarya.

Correct AnswerverifiedShow Answer

Please select the FALSE statement regarding taxonomic hierarchy.

Correct AnswerverifiedShow Answer

You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates

Correct AnswerverifiedShow Answer

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