Question 1

Whether an organism is a phototroph or a chemotroph depends on its source of energy.

Accepted Answer

A) True 
 B)False

Question 2

Which two enzymes catalyze the steps converting the toxic superoxide ion to less harmful oxygen gas?

Accepted Answer

A)  catalase and hydrogen peroxidases
B)  superoxide dismutase and hydrogen peroxidase
C)  superoxide dismutase and catalase
D)  catalase and oxidase
E)  superoxide dismutase and oxidaseF) A) and B)
G) B) and E)

Question 3

Why do bacterial cells require calcium?

Accepted Answer

A)  It stabilizes the cell wall.
B)  It stabilizes the ribosomes.
C)  It stabilizes the nucleoid.
D)  It maintains cellular pH.
E)  It makes strong bones.F) C) and D)
G) B) and E)

Question 4

Which term describes human pathogens?

Accepted Answer

A)  psychrophiles
B)  thermophiles
C)  halophiles
D)  mesophiles
E)  acidophilesF) A) and E)
G) C) and E)

Question 5

The majority of microbes live and grow in habitats between pH 7 and 9.

Accepted Answer

A) True 
 B)False

Question 6

Organisms that feed on dead organisms for nutrients are called

Accepted Answer

A)  saprobes.
B)  parasites.
C)  autotrophs.
D)  lithoautotrophs.
E)  phototrophs.F) B) and C)
G) B) and E)

Question 7

An organism that grows slowly in the cold but has an optimum growth temperature of 32°C is called

Accepted Answer

A)  an extremophile.
B)  a thermophile.
C)  a psychrophile.
D)  a facultative psychrophile.
E)  thermoduric.F) D) and E)
G) A) and B)

Question 8

The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

Accepted Answer

A)  facilitated diffusion.
B)  diffusion.
C)  active transport.
D)  osmosis.
E)  endocytosis.F) D) and E)
G) A) and B)

Question 9

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

Accepted Answer

A) True 
 B)False

Question 10

Bacteria have an average generation time of 24 hours.

Accepted Answer

A) True 
 B)False

Question 11

The The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a _____ relationship.

Accepted Answer

A)  parasitic
B)  saprobic
C)  commensal
D)  mutualisticE) A) and B)
F) A) and C)

Question 12

The phase of the bacterial growth curve that shows the maximum rate of cell division is the

Accepted Answer

A)  lag phase.
B)  log phase.
C)  stationary phase.
D)  death phase.
E)  prophase.F) B) and D)
G) All of the above

Question 13

Obligate saprobes can adapt to a living host.

Accepted Answer

A) True 
 B)False

Question 14

The production of antibiotics is a form of amensalism called

Accepted Answer

A)  symbiosis.
B)  satellitism.
C)  antibiosis.
D)  mutualism.
E)  synergism.F) A) and E)
G) B) and E)

Question 15

Archaea as a group are not pathogens.This is because

Accepted Answer

A)  they evolved without mammals.
B)  mammals evolved special defenses against them.
C)  mammalian hosts do not meet their environmental requirements.
D)  they are out-competed by natural flora.E) B) and D)
F) B) and C)

Question 16

An organism that can exist in both oxygen and oxygen-free environments is a(n)

Accepted Answer

A)  aerobe.
B)  obligate aerobe.
C)  facultative anaerobe.
D)  microaerophile.
E)  obligate anaerobe.F) A) and E)
G) C) and E)

Question 17

The term obligate refers to

Accepted Answer

A)  the ability to exist in a wide range of conditions.
B)  existing in a very narrow niche.
C)  using chemicals for energy production.
D)  using light for energy production.
E)  using oxygen for metabolism.F) B) and E)
G) All of the above

Question 18

Which term refers to the diffusion of water through a semipermeable membrane?

Accepted Answer

A)  facilitated diffusion
B)  diffusion
C)  active transport
D)  osmosis
E)  endocytosisF) C) and D)
G) B) and D)

Question 19

Planktonic bacteria are more susceptible to antibiotics as compared to biofilm microorganisms.

Accepted Answer

A) True 
 B)False

Question 20

An organism that cannot grow without oxygen is a(n)

Accepted Answer

A)  aerobe.
B)  obligate aerobe.
C)  facultative anaerobe.
D)  microaerophile.
E)  obligate anaerobe.F) All of the above
G) B) and E)

Exam 7: Microbial Nutrition, Ecology, and Growth

An organism that grows slowly in the cold but has an optimum growth temperature of 32°C is called

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Obligate saprobes can adapt to a living host.

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Why do bacterial cells require calcium?

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Planktonic bacteria are more susceptible to antibiotics as compared to biofilm microorganisms.

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An organism that can exist in both oxygen and oxygen-free environments is a(n)

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An organism that cannot grow without oxygen is a(n)

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The production of antibiotics is a form of amensalism called

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The phase of the bacterial growth curve that shows the maximum rate of cell division is the

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Lithoautotrophs use inorganic nutrients for carbon and energy sources.

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Organisms that feed on dead organisms for nutrients are called

Correct AnswerverifiedShow Answer

Archaea as a group are not pathogens.This is because

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Which term refers to the diffusion of water through a semipermeable membrane?

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Whether an organism is a phototroph or a chemotroph depends on its source of energy.

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The term obligate refers to

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Which two enzymes catalyze the steps converting the toxic superoxide ion to less harmful oxygen gas?

Correct AnswerverifiedShow Answer

The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

Correct AnswerverifiedShow Answer

Bacteria have an average generation time of 24 hours.

Correct AnswerverifiedShow Answer

Which term describes human pathogens?

Correct AnswerverifiedShow Answer

The The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a _____ relationship.

Correct AnswerverifiedShow Answer

The majority of microbes live and grow in habitats between pH 7 and 9.

Correct AnswerverifiedShow Answer

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