Question 1

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) C) and D)
G) C) and E)

Question 2

Organisms that feed on dead organisms for nutrients are called

Accepted Answer

A)  saprobes.
B)  parasites.
C)  autotrophs.
D)  lithoautotrophs.
E)  phototrophs.F) A) and E)
G) None of the above

Question 3

Bacteria have an average generation time of 24 hours.

Accepted Answer

A) True 
 B)False

Question 4

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) C) and E)
G) B) and C)

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

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 C)
F) A) and B)

Question 7

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

Accepted Answer

A) True 
 B)False

Question 8

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) A) and D)
G) A) and B)

Question 9

Obligate saprobes can adapt to a living host.

Accepted Answer

A) True 
 B)False

Question 10

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) B) and C)
G) A) and B)

Question 11

Which term describes human pathogens?

Accepted Answer

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

Question 12

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) None of the above
G) D) and E)

Question 13

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) B) and C)
G) A) and E)

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

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 D)
G) C) and D)

Question 16

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) None of the above
F) B) and C)

Question 17

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) D) and E)
G) A) and B)

Question 18

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) B) and C)
G) A) and B)

Question 19

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

Accepted Answer

A) True 
 B)False

Question 20

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) C) and D)
G) A) and E)

Exam 7: Microbial Nutrition, Ecology, and Growth

Organisms that feed on dead organisms for nutrients are called

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

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Archaea as a group are not pathogens.This is because

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

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

Correct AnswerverifiedShow Answer

The term obligate refers to

Correct AnswerverifiedShow Answer

Obligate saprobes can adapt to a living host.

Correct AnswerverifiedShow Answer

Why do bacterial cells require calcium?

Correct AnswerverifiedShow Answer

Bacteria have an average generation time of 24 hours.

Correct AnswerverifiedShow Answer

The production of antibiotics is a form of amensalism called

Correct AnswerverifiedShow Answer

Which term describes human pathogens?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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