Deck 10: Identification and Classification of Prokaryotes

Question 1

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

A)usually contain a pH indicator in the media.
B)usually contain blood.
C)usually require the addition of various reagents before the color is evident.
D)is due to a breakdown of a colorless reagent.

Answer 1

A

Question 2

The basic taxonomic unit in the classification scheme of plants and animals is

A)kingdom.
B)class.
C)order.
D)genus.
E)species.

Answer 2

E

Question 3

A selective growth medium

A)allows only certain bacteria to grow.
B)allows all bacteria to grow.
C)allows no bacteria to grow.
D)accentuates differences between the growing bacteria.

Answer 3

A

Question 4

From most general to most specific, which is the correct order?

A)phylum, class, kingdom, order, family, genus, species
B)kingdom, phylum, class, order, family, genus, species
C)kingdom, phylum, family, class, order, genus, species
D)kingdom, order, family, genus, phylum, class, species

Question 5

Gram-positive encapsulated diplococci found in sputum is indicative of

A)E.coli.
B)Pseudomonas.
C)Streptococcus pneumoniae.
D)Neisseria gonorrhea.

Question 6

In 1970 Stanier proposed that classification be based on

A)evolution.
B)Gram stain.
C)physiology.
D)DNA sequence.

Question 7

Mycobacterium tuberculosis is one of the few species of bacteria that

A)are encapsulated.
B)stain Gram-negative.
C)are acid fast.
D)stain Gram-positive.

Question 8

Very often clinically relevant information may be obtained by examining

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.

Question 9

Intracellular Gram-negative diplococci found in a urethral sample from a male is indicative of

A)E.coli.
B)Pseudomonas.
C)Streptococcus pneumoniae.
D)Neisseria gonorrhea.

Question 10

A soluble greenish pigment is produced by

A)Serratia marcescens.
B)
C)Pseudomonas aeruginosa.
D)streptococci.

Question 11

Woese

A)was involved in determining rRNA sequences.
B)proposed breaking prokaryotes into two groups.
C)proposed breaking eukaryotes into Archaea and Bacteria.
D)was involved in refining the Gram stain for classification purposes.
E)was involved in determining rRNA sequences AND proposed breaking prokaryotes into two groups.

Question 12

The three domain classification scheme uses

A)order, phylum, class.
B)plants, animals, bacteria.
C)protista, prokaryotae, fungaea.
D)Archaea, Bacteria, Eucarya.

Question 13

Streptococcus pyogenes would be

A)beta hemolytic and catalase negative.
B)beta hemolytic and catalase positive.
C)alpha hemolytic and catalase negative.
D)alpha hemolytic and catalase positive.

Question 14

Which technique(s) is/are used to help identify and classify bacteria?

A)microscopic examination
B)culture characteristics
C)biochemical tests
D)nucleic acid analysis
E)All of the choices are correct.

Question 15

In the 1930s Kluyver and van Niel proposed a classification scheme based on

A)Gram reactions.
B)biochemical relationships.
C)presumed evolutionary relationships.
D)DNA sequences.

Question 16

An early attempt by Cohn at bacterial classification grouped bacteria according to their

A)biochemistry.
B)Gram stain.
C)shape.
D)arrangement.

Question 17

In higher organisms, successful mating can occur between members of the same

A)genus.
B)species.
C)class.
D)order.

Question 18

In 1908 Orla-Jensen suggested that bacteria be grouped according to their

A)arrangement.
B)morphology.
C)physiology.
D)Gram stain.

Question 19

The reference for taxonomic descriptions of bacteria is

A)Gray's Anatomy.
B)Websters Manual of Taxonomic Bacteriology.
C)Bergey's Manual of Systematic Bacteriology.
D)Bacteriology.

Question 20

The name Lactococcus (Streptococcus) lactis

A)indicates that the subgenus is Streptococcus.
B)indicates that the family is Lactococcus.
C)indicates that Streptococcus is the old genus name.
D)indicates that Lactococcus is the old class name.

Question 21

The point at which two organisms diverged from a common ancestor

A)can be determined by comparing the nucleic acid sequences.
B)depends on translational control.
C)depends on metabolism.
D)is determined on MacConkeys media.

Question 22

Fatty acid analysis

A)can be used to identify Gram-negative bacteria.
B)can be used to identify Gram-positive bacteria.
C)uses gas chromatography to analyze fatty acid methyl esters.
D)requires that cells be grown under standardized conditions.
E)All of the above

Question 23

Which of the rRNA molecules has proven the most useful in taxonomy/identification?

A)5S
B)80S
C)16S
D)23S

Question 24

DNA probes have been very useful in

A)coding the DNA of organisms grown in vivo.
B)identifying organisms in pure culture.
C)detecting toxins.
D)diagnosing diseases of protozoa.

Question 25

Strain differences are helpful in

A)replica plating.
B)electrophoresis.
C)transformation.
D)transduction.
E)tracing the source of outbreaks of disease.

Question 26

Two isolates with identical RFLPs are considered

A)the same strain.
B)different strains.
C)possibly the same strain.
D)different genera.

Question 27

Phenotypically identical bacteria

A)look the same.
B)are genetically exactly the same.
C)may be told apart by DNA sequence analysis.
D)may not be told apart by any means.
E)look the same AND may be told apart by DNA sequence analysis.

Question 28

The relatedness of organisms determined by counting common characteristics is called

A)evolutionary taxonomy.
B)amino acid sequences.
C)DNA sequences.
D)numerical taxonomy.
E)suggests the organisms are very closely related at the species level AND means the GC content is 45%.

Question 29

Serological methods

A)are useful in identifying unknown bacterium.
B)rely on the specificity of an antibody-antigen interaction.
C)may be simple and rapid.
D)All of the choices are correct.

Question 30

Nucleic acid techniques have great power as diagnostic tools because they may be

A)very specific.
B)quick and easy to perform.
C)used to enhance the growth of bacteria.
D)used to selectively inhibit the growth of certain bacteria.

Question 31

Phage typing

A)is useful for determining eukaryotic cell types.
B)is used to extract DNA from cells.
C)is used to distinguish bacterial strains.
D)is dependent on the type of eukaryotic cell.
E)is used to distinguish bacterial strains AND is dependent on the type of eukaryotic cell.

Question 32

To study the phylogeny of eukaryotes

A)16S rRNA is used.
B)34S rRNA is used.
C)80S rRNA is used.
D)18S rRNA is used.

Question 33

The more closely related two organisms are,

A)the less they look alike.
B)the more similar the nucleic acid sequence.
C)the less similar the nucleic acid sequence.
D)the more they are phenotypically similar.
E)the more similar the nucleic acid sequence AND the more they are phenotypically similar.

Question 34

E. coli 0157:H7

A)is Gram-positive.
B)is a normal constituent of the intestinal tract.
C)does not ferment sorbitol.
D)produces a toxin.
E)does not ferment sorbitol AND produces a toxin.

Question 35

API^TM, Enterotube^TM and Vitek^TM are all

A)methods for extracting DNA from bacteria.
B)used to measure gas production.
C)commercially available methods used to identify bacteria.
D)used to show the presence of bacteria in a sample.

Question 36

A breath test assaying for radioactive carbon dioxide may be used to indicate the presence of

A)E.coli.
B)Pseudomonas.
C)Streptococcus pyogenes.
D)Helicobacter pylori.

Question 37

Organisms that grow very slowly, are non-culturable, are present in very small numbers or are mixed with a number of other bacteria may still be identified using

A)Southern blotting.
B)replica plating.
C)PCR.
D)gas chromatography of fatty acids.

Question 38

The ticks of a genetic clock are measured by the

A)number of random mutations.
B)number of dead cells.
C)amount of RNA.
D)amount of DNA.

Question 39

In

A)specific type of DNA present.
B)specific genus.
C)general family.
D)the specific LPS and flagella type present.

Question 40

Modern approaches to evolutionary taxonomy often involve

A)biochemical differences.
B)comparison of DNA and RNA.
C)protein similarities.
D)lactose fermentation.

Question 41

Horizontal DNA transfer may make it more difficult to construct phylogenetic trees.

Question 42

The three domain systems consist of Archaea, Bacteria, Eucarya.

Question 43

Sequencing of rRNA is useful for

A)determining evolutionary relationships.
B)determining protein sequences.
C)identification of unknown bacteria.
D)serological relationships.
E)determining evolutionary relationships AND identification of unknown bacteria.

Question 44

Disagreements between conclusions obtained from rDNA data and other techniques may be explained by

A)horizontal DNA transfer.
B)vertical DNA transfer.
C)the difference in translation machinery.
D)vertical RNA transfer.

Question 45

A DNA similarity of 75% between two organisms

A)suggests the organisms are very closely related at the species level.
B)suggests the organisms are not related.
C)suggests the organisms may or may not be related.
D)means the GC content is 45%.

Question 46

Why might it be easier to determine the bacterium that caused pneumonia than one that caused a wound infection?

A)There are very few microorganisms that can cause pneumonia, while there are many that can cause wound infections.
B)The lungs are generally free of bacteria, while the skin may have a number of different types of bacteria on it.This could complicate identification processes for a wound infection, as bacteria normally found on the skin may be in the wound along with the particular bacterium causing the infection.
C)We have much better tests for bacteria in the lungs than we do in wounds.
D)The techniques of 16S rRNA sequencing are easier to perform on a sample taken from the lungs than a sample taken from a wound.

Question 47

Numerical taxonomy uses a battery of genotypic characteristics to classify bacteria.

Question 48

Serratia marcescens are red when incubated at 37°C.

Question 49

If the GC content of two organisms is 45% in both

A)they are definitely related.
B)they are definitely not related.
C)they may or may not be related.
D)the AT content is 65%.
E)they are definitely related AND the AT content is 65%.

Question 50

rRNA sequence comparisons are useful for determining evolutionary relationships.

Question 51

If each of two bacteria have a %GC of 50%, this means that they are both definitely closely related.

Question 52

Phylogenetic relationships between prokaryotes are most accurately determined using

A)phenotypic characterizations.
B)genotypic information.
C)the fossil record.
D)carbon dating.
E)phenotypic characterizations AND genotypic information.

Question 53

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

Question 54

A sample must contain many microorganisms in order to see any using microscopy techniques. Why?

A)The area on a microscope slide is very large compared to the relative size of microbes, and you take a very small amount of your sample to place on the slide surface.Therefore, you must have a large number of microbes initially in the culture to increase the chances that you'll come across one or more when looking at the slide surface through the magnifying lenses of the microscope.
B)Bacteria are very small, of course.If you don't have a LOT of them, how are you going to see them?
C)This is false-microscopy allows us to magnify a specimen to the point where we would be able to visualize even just a few microbes on the surface of the slide.As such, even if there are only a few microbes in a sample, we could easily visualize them with a microscope.
D)Microscopes only magnify what's on the slide.If you don't have a lot of microbes on the slide surface, you can't magnify the specimen enough to see them as individual cells.

Question 55

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

Question 56

When DNA probes are used to identify bacterial DNA similarities by hybridization, the probe DNA is heated and the template DNA is treated to separate the 2 strands. Why would the probe DNA be heated?

A)This is the only way to properly label the probe DNA.
B)The probe DNA is single-stranded, but it may have folded back on itself and formed portions that are double-stranded.Heating it up breaks any possible hydrogen bonds that may have formed, returning it to a single-stranded state prior to hybridization.
C)Heating it up activates the tag on the probe DNA before it hybridizes to the bacterial template DNA.
D)DNA hybridization can only take place at high temperatures, so all the DNA must be heated up prior to hybridization.

Question 57

Why are molecular methods particularly useful for identification of microbes when they are difficult to grow?

A)While all microbes can (and should) be grown for identification purposes, sometimes it's simply faster to use a molecular technique.
B)They AREN'T useful-growing a microbe is clearly the only way to properly identify it.
C)Since all microbes use DNA, and we can sometimes detect and identify them through even very small amounts of their DNA, molecular methods allow us to identify microbes even when they can't be grown at all.
D)Molecular methods are far cheaper methods than growing microbes for identification.

Question 58

Explain the difference between a biotype and a serotype.

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).

Question 59

Size and shape may allow one to differentiate between a bacterium, fungus, or protozoan.

Question 60

Based on DNA hybridization, humans and chimpanzees are the same species.