Question 1

Which gammaproteobacteria genera include species that oxidize H₂S to S⁰?

Accepted Answer

A)   Escherichia and Enterobacter
B)   Chromatium and Beggiatoa
C)   Klebsiella and Shigella
D)   Proteus and Erwinia
E)   Rhodobacter and NitrosomonasF) A) and E)
G) None of the above

Question 2

Dehalobacter restrictus conducts anaerobic respiration by

Accepted Answer

A)   reducing aromatic rings of lignin-derived compounds.
B)   donating electrons to Fe3+, converting it to Fe2+ in mine ores.
C)   donating electrons to Cl atoms, effectively performing dechlorination.
D)   donating electrons to NO3-, yielding NO2-.
E)   donating electrons to SO42-, yielding HS-.F) All of the above
G) D) and E)

Question 3

Where do Chromatium cells store sulfur?

Accepted Answer

A)   in cytoplasmic granules
B)   in periplasmic granules
C)   in attached sulfur globules
D)   in their immediate environment
E)   in cytoplasmic vacuolesF) None of the above
G) B) and D)

Question 4

Discuss the chemical nature of mycolic acids and some of the traits they confer to organisms that possess them.

Accepted Answer

Mycolic acids are a diverse class of sug...

Question 5

Which of the following is NOT correct about the outer membrane of Gram-negative proteobacterial cell wall?

Accepted Answer

A)   It has receptor proteins and porins.
B)   In pathogens, lipopolysaccharide facilitates phagocytosis.
C)   Lipopolysaccharide is toxic when released by dying cells.
D)   It is a lipid bilayer membrane.
E)   Lipopolysaccharide is absent in the cytoplasmic membrane.F) D) and E)
G) A) and B)

Question 6

Clades of microbes that are recently defined or characterized are referred to as

Accepted Answer

A)   hyperthermophiles.
B)   archaea.
C)   phyla.
D)   deep branching.
E)   emerging.F) A) and B)
G) D) and E)

Question 7

Which of the following statements is NOT correct regarding the life cycle of Chlamydia?

Accepted Answer

A)   Elementary bodies are taken up by the host cells via endocytosis.
B)   Reticulate bodies differentiate from elementary bodies outside the host cell.
C)   A reticulate body may persist in the host cell for long periods.
D)   Reticulate bodies replicate and develop into elementary bodies.
E)   Elementary bodies are metabolically inert with a compacted chromosome, resembling spores.F) B) and E)
G) A) and C)

Question 8

All of the following are mechanisms that provide an anoxic environment for nitrogen fixation in cyanobacteria EXCEPT

Accepted Answer

A)   formation of heterocysts.
B)   formation of chlorosomes.
C)   temporal separation of photosynthesis and nitrogen fixation.
D)   accumulation of large aggregates of cells.
E)   symbiotic associations with fungi or plants.F) C) and E)
G) A) and C)

Question 9

What distinguishes bacterial cell walls from those in archaea and eukarya?

Accepted Answer

Most bacterial cells possess a cell wall...

Question 10

Bacteria are widely diverse in their cell structure, metabolism, and ecological adaptations, but share some major common traits. Which of the following statements is NOT true?

Accepted Answer

A)   They share common features in central apparatus for gene expression and translation.
B)   Bacterial gene expression mechanisms differ from those of the eukaryotes, which underlies the selective activity of many antibiotics.
C)   Some archaeal cell walls are composed of pseudopeptidoglycan and may have fundamentally different antibiotic sensitivity than bacteria.
D)   Mycoplasmas contain abnormal peptidoglycans and are thus not susceptible to antibiotics.
E)   In bacteria, variant forms of peptidoglycan distinguish different species.F) A) and C)
G) A) and E)

Question 11

Which genus within the spirochetes includes the causative agent of Lyme disease?

Accepted Answer

A)   Treponema
B)   Holandina
C)   Leptospira
D)   Borrelia
E)   SpirochaetaF) B) and D)
G) C) and D)

Question 12

The epsilonproteobacterium Helicobacter pylori is the cause of gastritis and stomach ulcers. What mechanism allows it to survive the acidic conditions of the mammalian stomach?

Accepted Answer

H. pylori and related species grow prima...

Question 13

The ________ lack cell walls and have a double membrane around the nucleoid; their tolerance for low concentrations of nutrients is called ________.

Accepted Answer

A)   Verrucomicrobia; ectosymbiosis
B)   Planctomycetes; oligotrophy
C)   Chlamydiae; endosymbiosis
D)   Cyanobacteria; oligotrophy
E)   Firmicutes; piezophilyF) D) and E)
G) None of the above

Question 14

In order to learn what makes proteins stable in thermophilic bacteria, how should the amino acids or motifs that are involved in conferring thermostability to proteins be explored?

Accepted Answer

Thermostability of proteins can be deter...

Question 15

How do Bacteroides fragilis and B. thetaiotaomicron contribute to 15% of human caloric intake? Are there other benefits provided by these microbes to human health? Are they potentially pathogenic?

Accepted Answer

Their main source of energy is fermentat...

Question 16

Corynebacterium species have a particular type of cell division that can be described as

Accepted Answer

A)   "half-snapping."
B)   the formation of reticulate bodies.
C)   the formation of a forespore and a mother cell.
D)   stalking.
E)   "live birth."F) A) and B)
G) C) and E)

Question 17

Describe the cell wall of Verrucomicrobia. How could these organisms have acquired this trait?

Accepted Answer

Verrucomicrobia have peptidoglycan cell ...

Question 18

Which of the following is an extremophile?

Accepted Answer

A)   Bacillus alkalophilus
B)   Bacillus thuringiensis
C)   Bacillus subtilis
D)   Clostridium botulinum
E)   Clostridium tetaniF) B) and D)
G) A) and B)

Question 19

Which of the following is NOT correct with respect to the mycoplasmas?

Accepted Answer

A)   They have lost their cell wall and the S-layer through reductive evolution.
B)   Their cells maintain their shape through a type of cytoskeleton.
C)   When cultured on agar, their colonies have a "fried-egg" shape.
D)   They are parasites of all kinds of multicellular organisms.
E)   They have some of the largest bacterial genomes.F) A) and B)
G) D) and E)

Question 20

What is unique about the genome of Borrelia species?

Accepted Answer

Borrelia species have multipartite genom...

Exam 18: Bacterial Diversity

How do Bacteroides fragilis and B. thetaiotaomicron contribute to 15% of human caloric intake? Are there other benefits provided by these microbes to human health? Are they potentially pathogenic?

Correct AnswerverifiedTheir main source of energy is fermentat...View AnswerShow Answer

Corynebacterium species have a particular type of cell division that can be described as

Correct AnswerverifiedShow Answer

Dehalobacter restrictus conducts anaerobic respiration by

Correct AnswerverifiedShow Answer

Bacteria are widely diverse in their cell structure, metabolism, and ecological adaptations, but share some major common traits. Which of the following statements is NOT true?

Correct AnswerverifiedShow Answer

Which gammaproteobacteria genera include species that oxidize H₂S to S⁰?

Correct AnswerverifiedShow Answer

The epsilonproteobacterium Helicobacter pylori is the cause of gastritis and stomach ulcers. What mechanism allows it to survive the acidic conditions of the mammalian stomach?

Correct AnswerverifiedH. pylori and related species grow prima...View AnswerShow Answer

In order to learn what makes proteins stable in thermophilic bacteria, how should the amino acids or motifs that are involved in conferring thermostability to proteins be explored?

Correct AnswerverifiedThermostability of proteins can be deter...View AnswerShow Answer

All of the following are mechanisms that provide an anoxic environment for nitrogen fixation in cyanobacteria EXCEPT

Correct AnswerverifiedShow Answer

What is unique about the genome of Borrelia species?

Correct AnswerverifiedBorrelia species have multipartite genom...View AnswerShow Answer

Discuss the chemical nature of mycolic acids and some of the traits they confer to organisms that possess them.

Correct AnswerverifiedMycolic acids are a diverse class of sug...View AnswerShow Answer

The ________ lack cell walls and have a double membrane around the nucleoid; their tolerance for low concentrations of nutrients is called ________.

Correct AnswerverifiedShow Answer

Describe the cell wall of Verrucomicrobia. How could these organisms have acquired this trait?

Correct AnswerverifiedVerrucomicrobia have peptidoglycan cell ...View AnswerShow Answer

Clades of microbes that are recently defined or characterized are referred to as

Correct AnswerverifiedShow Answer

What distinguishes bacterial cell walls from those in archaea and eukarya?

Correct AnswerverifiedMost bacterial cells possess a cell wall...View AnswerShow Answer

Which genus within the spirochetes includes the causative agent of Lyme disease?

Correct AnswerverifiedShow Answer

Where do Chromatium cells store sulfur?

Correct AnswerverifiedShow Answer

Which of the following is NOT correct about the outer membrane of Gram-negative proteobacterial cell wall?

Correct AnswerverifiedShow Answer

Which of the following is an extremophile?

Correct AnswerverifiedShow Answer

Which of the following statements is NOT correct regarding the life cycle of Chlamydia?

Correct AnswerverifiedShow Answer

Which of the following is NOT correct with respect to the mycoplasmas?

Correct AnswerverifiedShow Answer

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Their main source of energy is fermentat...
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H. pylori and related species grow prima...
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Thermostability of proteins can be deter...
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Correct Answer
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Correct Answer
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Borrelia species have multipartite genom...
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Correct Answer
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Mycolic acids are a diverse class of sug...
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The lack cell walls and have a double membrane around the nucleoid; their tolerance for low concentrations of nutrients is called .

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Correct Answer
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Verrucomicrobia have peptidoglycan cell ...
View Answer

Correct Answer
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Correct Answer
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Most bacterial cells possess a cell wall...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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