Question 1

In nature, bacteria

Accepted Answer

A)   often grow in close association with many other kinds of organisms.
B)   may remain in a prolonged exponential phase.
C)   frequently synthesize structures such as slime layers.
D)   may adhere to surfaces by means of pili and slime layers.
E)   All of the choices are correct.F) D) and E)
G) A) and B)

Question 2

Shake tubes are used to determine the

Accepted Answer

A)   pH requirements for bacterial growth.
B)   temperature requirements for bacterial growth.
C)   oxygen requirements for bacterial growth.
D)   salt requirements for bacterial growth.E) All of the above
F) B) and C)

Question 3

Candle jars are usually used to

Accepted Answer

A)   store candles.
B)   provide an atmosphere with CO2.
C)   stimulate the growth of obligate anaerobes.
D)   prevent the growth of obligate aerobes.
E)   provide an atmosphere with CO2 AND stimulate the growth of obligate anaerobes.F) D) and E)
G) B) and E)

Question 4

Chemoheterotrophs

Accepted Answer

A)   use sunlight as an energy source.
B)   use pre-formed organic molecules as a carbon source.
C)   use pre-formed organic molecules as an energy source.
D)   use inorganic chemicals as an energy source.
E)   use pre-formed organic molecules as a carbon source AND as an energy source.F) C) and D)
G) A) and C)

Question 5

When doing experiments with bacteria

Accepted Answer

A)   it is usually not necessary to standardize which stage of growth is used.
B)   it is best to use colonies as all the bacteria in a colony are at the same stage of growth.
C)   it is best to use bacteria from the same stage of growth.
D)   the age of the bacteria is not important.E) None of the above
F) A) and B)

Question 6

Prokaryotic cells divide by a process known as

Accepted Answer

A)   conjugation.
B)   mitosis.
C)   binary fusion.
D)   binary fission.E) None of the above
F) All of the above

Question 7

Differential media only allows certain bacteria to grow.

Accepted Answer

A) True 
 B)False

Question 8

A hot tub (approx. 104 deg. F or 40 deg. C)  would most likely contain

Accepted Answer

A)   psychrophiles.
B)   partiers.
C)   thermophiles.
D)   mesophiles.E) A) and C)
F) All of the above D

Question 9

The simplest technique for isolating bacteria in growth media is referred to as the

Accepted Answer

A)   pour plate method.
B)   streak plate method.
C)   serial dilution method.
D)   MPN method.E) B) and C)
F) C) and D)

Question 10

Organisms that use organic molecules as their source of carbon are called

Accepted Answer

A)   chemotrophs.
B)   organoheterotrophs.
C)   heterotrophs.
D)   autotrophs.E) A) and C)
F) None of the above

Question 11

Organisms that use CO2 as their source of carbon are called

Accepted Answer

A)   organotrophs.
B)   heterotrophs.
C)   autotrophs.
D)   chemotrophs.E) A) and B)
F) A) and C) C

Question 12

Prokaryotes are the only organisms able to use atmospheric nitrogen as a nitrogen source.

Accepted Answer

A) True 
 B)False  True

Question 13

The solidifying agent used most successfully in bacterial nutrient media is

Accepted Answer

A)   gelatin.
B)   peptone.
C)   agar.
D)   starch.E) A) and D)
F) B) and C)

Question 14

The lag phase of the bacterial growth curve is marked by

Accepted Answer

A)   a decrease in cell mass.
B)   dormant, metabolically inactive cells.
C)   metabolically active cells.
D)   vigorously dividing cells.E) A) and C)
F) None of the above

Question 15

The scientist that contributed most to the development of pure culture techniques was

Accepted Answer

A)   Alexander Fleming.
B)   Louis Pasteur.
C)   Edward Jenner.
D)   Robert Koch.E) A) and B)
F) B) and C)

Question 16

In the cultivation of microaerophilic and anaerobic bacteria,

Accepted Answer

A)   a(n)  candle/anaerobe jar is sufficient.
B)   atmospheric oxygen in a(n)  candle/anaerobe jar is converted to water.
C)   a catalyst is used that makes hydrogen and carbon dioxide in a(n)  candle/anaerobe jar.
D)   oxidizing agents are incorporated into the media that react with oxygen.E) A) and B)
F) B) and D)

Question 17

A physician sends a stool sample to your lab, and wants to know if there are lactose fermenting microbes in the sample. How might you determine if these microbes are present or not from this mixed-microbe specimen?

Accepted Answer

A)   Streak the sample for isolation on Thayer-Martin agar (which contains lactose and particular antibiotics for selectivity) .
B)   Streak the sample for isolation on a blood agar plate (which contains lactose AND red blood cells that enrich the culture for iron) .
C)   Streak the sample for isolation on a MacConkey agar plate (which contains lactose and a pH indicator that turns pink when acid byproducts are present) .
D)   None of the above would work-there's no way to reliably determine this feature from the specimen given.E) B) and C)
F) A) and D)

Question 18

Organisms may derive energy from

Accepted Answer

A)   sunlight.
B)   metabolizing chemical compounds.
C)   little tiny AAAAAAAAA batteries.
D)   temperature gradients.
E)   sunlight AND metabolizing chemical compounds.F) A) and D)
G) B) and C)

Question 19

It is assumed that every colony observed on a streak plate arose from a single bacterium.

Accepted Answer

A) True 
 B)False

Question 20

A urine sample with more than 100,000 organisms is considered indicative of infection. A urine sample containing 5,000 bacteria, with a generation time of 30 minutes, sits for 3 hours before finally being assayed. How many bacteria will then be present within the sample?

Accepted Answer

A)   10,000
B)   64,000
C)   100,000
D)   320,000E) All of the above
F) C) and D)

Exam 4: Dynamics of Prokaryotic Growth

In nature, bacteria

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Shake tubes are used to determine the

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Candle jars are usually used to

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Chemoheterotrophs

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When doing experiments with bacteria

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Prokaryotic cells divide by a process known as

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Differential media only allows certain bacteria to grow.

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A hot tub (approx. 104 deg. F or 40 deg. C) would most likely contain

Correct AnswerverifiedD

The simplest technique for isolating bacteria in growth media is referred to as the

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Organisms that use organic molecules as their source of carbon are called

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Organisms that use CO2 as their source of carbon are called

Correct AnswerverifiedC

Prokaryotes are the only organisms able to use atmospheric nitrogen as a nitrogen source.

Correct AnswerverifiedTrue

The solidifying agent used most successfully in bacterial nutrient media is

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The lag phase of the bacterial growth curve is marked by

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The scientist that contributed most to the development of pure culture techniques was

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In the cultivation of microaerophilic and anaerobic bacteria,

Correct AnswerverifiedShow Answer

A physician sends a stool sample to your lab, and wants to know if there are lactose fermenting microbes in the sample. How might you determine if these microbes are present or not from this mixed-microbe specimen?

Correct AnswerverifiedShow Answer

Organisms may derive energy from

Correct AnswerverifiedShow Answer

It is assumed that every colony observed on a streak plate arose from a single bacterium.

Correct AnswerverifiedShow Answer

A urine sample with more than 100,000 organisms is considered indicative of infection. A urine sample containing 5,000 bacteria, with a generation time of 30 minutes, sits for 3 hours before finally being assayed. How many bacteria will then be present within the sample?

Correct AnswerverifiedShow Answer

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D

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Organisms that use CO₂ as their source of carbon are called

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C

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True

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