Question 1

The bio?lm that forms in your shower ("shower curtain scum")  can tolerate exposure to hot water when you shower and is resistant to desiccation between showers. The microbes in the bio?lm are not endospores, so what is the best explanation for their survival under these conditions?

Accepted Answer

A)   Bio?ms are composed of diverse microbes, and within each bio?lm, there are certain to be endospore-formers and thermophiles.
B)   Although some microbes will be killed, those embedded deeply within the bio?lm are protected from environmental challenges.
C)   The shower hasn't been thoroughly cleaned in a while, and when I really scrub it, the microbes will all be killed.
D)   Dead skin cells continuously replenish the bio?lm, and organic soaps provide a continuous carbon source.E) B) and C)
F) A) and D)

Question 2

Obligate saprobes can adapt to a living host.

Accepted Answer

A) True 
 B)False

Question 3

A Coulter counter can count viable cells as well as determine their size.

Accepted Answer

A) True 
 B)False

Question 4

An organism that cannot tolerate an oxygen environment is a/an ______.

Accepted Answer

A)   obligate aerobe
B)   microaerophile
C)   facultative anaerobe
D)   aerobe
E)   obligate anaerobeF) A) and D)
G) None of the above

Question 5

The toxic superoxide ion is converted to harmless oxygen by two enzymes, _______.

Accepted Answer

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

Question 6

Bacteria like E. coli have an average generation time of 24 hours.

Accepted Answer

A) True 
 B)False

Question 7

A halophile would grow best in ______.

Accepted Answer

A)   arid, desert soil
B)   fresh water ponds
C)   acid pools
D)   salt lakes
E)   hot geyser springsF) B) and C)
G) None of the above

Question 8

When microbes live independently but cooperate and share nutrients, it is called ______.

Accepted Answer

A)   synergism
B)   symbiosis
C)   antibiosis
D)   mutualismE) A) and C)
F) C) and D)

Question 9

Which of the following is not a major element of a microbial cell?

Accepted Answer

A)   Nitrogen
B)   Oxygen
C)   Carbon
D)   Hydrogen
E)   CopperF) C) and D)
G) All of the above

Question 10

Which of the following properties is likely to be found in a pioneer colonizer of a bioﬁlm on an artiﬁcial joint implant?

Accepted Answer

A)   No susceptibility to reactive oxygen species like peroxides
B)   The ability to grow at thermophilic body temperature (37 º
C)  
C)   The ability to use the titanium from the implant as an energy source
D)   Surface structures for attaching to tissueE) B) and C)
F) None of the above

Question 11

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

Accepted Answer

A) True 
 B)False

Question 12

The cell wall will help prevent the cell from bursting in ______ conditions.

Accepted Answer

A)   mesotonic
B)   hypotonic
C)   isotonic
D)   hypertonicE) All of the above
F) A) and D)

Question 13

Inorganic nitrogen must be converted to ammonia to be used by a cell.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

A)   prophase
B)   death phase
C)   lag phase
D)   stationary phase
E)   exponential phaseF) B) and E)
G) C) and E)

Question 15

The term facultative refers to _______.

Accepted Answer

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

Question 16

Organisms that feed on dead organisms for nutrients are called ______.

Accepted Answer

A)   parasites
B)   saprobes
C)   autotrophs
D)   phototrophs
E)   lithoautotrophsF) A) and B)
G) C) and E)

Question 17

A closed culture system is used to determine a population growth curve.

Accepted Answer

A) True 
 B)False

Question 18

A microaerophile _______.

Accepted Answer

A)   requires a small amount of oxygen but won't grow at normal atmospheric levels of oxygen
B)   grows best in an anaerobic jar
C)   grows with or without oxygen
D)   needs normal atmospheric levels of oxygenE) All of the above
F) A) and B)

Question 19

Anaerobes can be cultured in a CO₂ environment.

Accepted Answer

A) True 
 B)False

Question 20

In a close relationship, a change in one partner that results from a change in the other partner is termed ______.

Accepted Answer

A)   coevolution
B)   antibiosis
C)   synergism
D)   mutualism
E)   symbiosisF) B) and C)
G) None of the above

Exam 7: Microbial Nutrition and Growth

The bio?lm that forms in your shower ("shower curtain scum") can tolerate exposure to hot water when you shower and is resistant to desiccation between showers. The microbes in the bio?lm are not endospores, so what is the best explanation for their survival under these conditions?

Correct AnswerverifiedShow Answer

Anaerobes can be cultured in a CO₂ environment.

Correct AnswerverifiedShow Answer

Obligate saprobes can adapt to a living host.

Correct AnswerverifiedShow Answer

The toxic superoxide ion is converted to harmless oxygen by two enzymes, _______.

Correct AnswerverifiedShow Answer

A microaerophile _______.

Correct AnswerverifiedShow Answer

Inorganic nitrogen must be converted to ammonia to be used by a cell.

Correct AnswerverifiedShow Answer

The term facultative refers to _______.

Correct AnswerverifiedShow Answer

Bacteria like E. coli have an average generation time of 24 hours.

Correct AnswerverifiedShow Answer

An organism that cannot tolerate an oxygen environment is a/an ______.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following is not a major element of a microbial cell?

Correct AnswerverifiedShow Answer

The cell wall will help prevent the cell from bursting in ______ conditions.

Correct AnswerverifiedShow Answer

A closed culture system is used to determine a population growth curve.

Correct AnswerverifiedShow Answer

When microbes live independently but cooperate and share nutrients, it is called ______.

Correct AnswerverifiedShow Answer

Organisms that feed on dead organisms for nutrients are called ______.

Correct AnswerverifiedShow Answer

A Coulter counter can count viable cells as well as determine their size.

Correct AnswerverifiedShow Answer

A halophile would grow best in ______.

Correct AnswerverifiedShow Answer

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

Correct AnswerverifiedShow Answer

Which of the following properties is likely to be found in a pioneer colonizer of a bioﬁlm on an artiﬁcial joint implant?

Correct AnswerverifiedShow Answer

In a close relationship, a change in one partner that results from a change in the other partner is termed ______.

Correct AnswerverifiedShow Answer

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