Question 1

Late log phase of the bacterial growth curve

Accepted Answer

A)  is characterized by the production of primary metabolites. 
B)  is characterized by the production of secondary metabolites. 
C)  is a transition into the death phase. 
D)  shows a decline in cell numbers. 
E)  is characterized by germination of endospores. 
A)  is characterized by the production of primary metabolites. 
B)  is characterized by the production of secondary metabolites. 
C)  is a transition into the death phase. 
D)  shows a decline in cell numbers. 
E)  is characterized by germination of endospores. B

Question 2

During which phase of the bacterial growth curve does the total number of viable (live) cells decline?

Accepted Answer

A)  Stationary 
B)  Lag 
C)  Exponential 
D)  Death 
E)  Infection 
A)  Stationary 
B)  Lag 
C)  Exponential 
D)  Death 
E)  Infection D

Question 3

A modification of the BCYE medium used to culture L. pneumophila is BCYE with DGVP. This medium contains glycine, polymixin B (an antifungal agent), and and vancomycin (antibiotic), as well as two dyes (bromocreson purple and bromthymol blue) that facilitate identification of the organism based on colony color. What type of medium is BCYE with DGVP?

Accepted Answer

A)  Selective 
B)  Differential 
C)  Selective AND differential 
D)  Liquid 
E)  Anaerobic 
A)  Selective 
B)  Differential 
C)  Selective AND differential 
D)  Liquid 
E)  Anaerobic C

Question 4

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 packet containing chemicals that generate CO2 and hydrogen is used in a(n) candle/anaerobic jar. 
D)  oxidizing agents are incorporated into the media that react with oxygen. 
E)  selective and differential media must always be used. 
A)  a(n) candle/anaerobe jar is sufficient. 
B)  atmospheric oxygen in a(n) candle/anaerobe jar is converted to water. 
C)  a packet containing chemicals that generate CO2 and hydrogen is used in a(n) candle/anaerobic jar. 
D)  oxidizing agents are incorporated into the media that react with oxygen. 
E)  selective and differential media must always be used.

Question 5

Shigella species and Salmonella species are classified as facultative anaerobes. You know that given this information, the bacteria in your patient's fecal culture will grow best

Accepted Answer

A)  in the absence of oxygen. 
B)  in the presence of oxygen. 
C)  at low levels of oxygen. 
D)  in high levels of carbon dioxide. 
E)  if catalase is added to the medium. 
A)  in the absence of oxygen. 
B)  in the presence of oxygen. 
C)  at low levels of oxygen. 
D)  in high levels of carbon dioxide. 
E)  if catalase is added to the medium.

Question 6

A medium that inhibits the growth of organisms other than the one being sought is called a(n)

Accepted Answer

A)  synthetic medium. 
B)  specific culture medium. 
C)  selective medium. 
D)  enrichment medium. 
E)  differential medium. 
A)  synthetic medium. 
B)  specific culture medium. 
C)  selective medium. 
D)  enrichment medium. 
E)  differential medium.

Question 7

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)  320,000 
B)  100,000 
C)  64,000 
D)  15,000 
E)  10,000 
A)  320,000 
B)  100,000 
C)  64,000 
D)  15,000 
E)  10,000

Question 8

You are culturing a new bacterium in the laboratory. You cannot find any glucose it the lab when you are making growth medium, so you decide to use honey instead. You add twice as much honey than is called for in the medium recipe, because you want to give the organism the best opportunity or growth. To your surprise, the organism does not grow on your modified medium. Select the most likely explanation.

Accepted Answer

A)  The growth medium became hypotonic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
B)  The growth medium became hypertonic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
C)  The growth medium became halophilic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
D)  The growth medium became hypertonic with the addition of so much honey; the bacteria underwent osmotic lysis and died. 
E)  The growth medium became hypotonic with the addition of so much honey; the bacteria underwent simple diffusion and burst. 
A)  The growth medium became hypotonic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
B)  The growth medium became hypertonic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
C)  The growth medium became halophilic with the addition of so much honey; the bacteria underwent plasmolysis and died. 
D)  The growth medium became hypertonic with the addition of so much honey; the bacteria underwent osmotic lysis and died. 
E)  The growth medium became hypotonic with the addition of so much honey; the bacteria underwent simple diffusion and burst.

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the

Accepted Answer

A)  lag phase. 
B)  exponential (log) phase. 
C)  stationary phase. 
D)  decline phase. 
E)  death phase. 
A)  lag phase. 
B)  exponential (log) phase. 
C)  stationary phase. 
D)  decline phase. 
E)  death phase.

Question 11

During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?

Accepted Answer

A)  Lag phase 
B)  Exponential phase 
C)  Stationary phase 
D)  Late log phase 
E)  Decline phase 
A)  Lag phase 
B)  Exponential phase 
C)  Stationary phase 
D)  Late log phase 
E)  Decline phase

Question 12

Organisms that use CO2 as their source of carbon are called

Accepted Answer

A)  organotrophs. 
B)  heterotrophs. 
C)  autotrophs. 
D)  chemotrophs. 
E)  carbonotrophs. 
A)  organotrophs. 
B)  heterotrophs. 
C)  autotrophs. 
D)  chemotrophs. 
E)  carbonotrophs.

Question 13

Peptone

Accepted Answer

A)  refers to a hydrolysate of carbohydrates used in growth media. 
B)  refers to a hydrolysate of proteins used in growth media. 
C)  consists of a water extract of beef. 
D)  consists of a mix of monosaccharides and oligosaccharides. 
E)  refers to a hydrolysate of proteins used in growth media AND consists of a water extract of beef. 
A)  refers to a hydrolysate of carbohydrates used in growth media. 
B)  refers to a hydrolysate of proteins used in growth media. 
C)  consists of a water extract of beef. 
D)  consists of a mix of monosaccharides and oligosaccharides. 
E)  refers to a hydrolysate of proteins used in growth media AND consists of a water extract of beef.

Question 14

You are a microbiologist working for a pharmaceutical company and discover a new secreted metabolite that can serve as a medication. Your company asks you to oversee the production of the metabolite. Which of the following does NOT need to be considered if you need to grow 5,000 liter cultures of bacteria for the purpose of harvesting the metabolite they secrete?

Accepted Answer

A)  The death rate of the bacteria after stationary phase is complete. 
B)  The ideal rate of input of new nutrients into the culture to maintain the cells in log phase. 
C)  The ideal rate of pulling off some of the culture in order to maintain the cells in log phase. 
D)  The best way to mix the large vat in order to keep nutrient levels, temperature, and oxygen levels constant. 
E)  The best way to keep the pH of the entire mixture at the ideal level to promote log phase growth. 
A)  The death rate of the bacteria after stationary phase is complete. 
B)  The ideal rate of input of new nutrients into the culture to maintain the cells in log phase. 
C)  The ideal rate of pulling off some of the culture in order to maintain the cells in log phase. 
D)  The best way to mix the large vat in order to keep nutrient levels, temperature, and oxygen levels constant. 
E)  The best way to keep the pH of the entire mixture at the ideal level to promote log phase growth.

Question 15

The solidifying agent used most successfully in bacterial nutrient media is

Accepted Answer

A)  gelatin. 
B)  peptone. 
C)  agar. 
D)  starch. 
E)  agarose. 
A)  gelatin. 
B)  peptone. 
C)  agar. 
D)  starch. 
E)  agarose.

Question 16

The prefix photo- indicates that an organism will make use of ________ for energy purposes.

Accepted Answer

A)  chemicals 
B)  organics 
C)  light 
D)  inorganics 
E)  water 
A)  chemicals 
B)  organics 
C)  light 
D)  inorganics 
E)  water

Question 17

A hot tub (with a water temperature of 104°F or 40°C) would most likely contain

Accepted Answer

A)  psychrophiles. 
B)  freezophiles. 
C)  mesophiles. 
D)  thermophiles. 
E)  hyperthermophiles. 
A)  psychrophiles. 
B)  freezophiles. 
C)  mesophiles. 
D)  thermophiles. 
E)  hyperthermophiles.

Question 18

Freezing is an effective means of destroying bacteria.

Accepted Answer

A) True 
 B)False

Question 19

Clostridium paradoxum grows optimally at 55°C, pH 9.3; it will not grow in the presence of O2. Please select the TRUE statement about this organism.

Accepted Answer

A)  It is spherical in shape. 
B)  It is a psychrophile. 
C)  It is an obligate anaerobe. 
D)  It is an acidophile. 
E)  It is an aerotolerant anaerobe. 
A)  It is spherical in shape. 
B)  It is a psychrophile. 
C)  It is an obligate anaerobe. 
D)  It is an acidophile. 
E)  It is an aerotolerant anaerobe.

Question 20

Prokaryotic cells divide by a process known as

Accepted Answer

A)  conjugation. 
B)  mitosis. 
C)  binary fusion. 
D)  binary fission. 
E)  meiosis. 
A)  conjugation. 
B)  mitosis. 
C)  binary fusion. 
D)  binary fission. 
E)  meiosis.

Exam 4: Dynamics of Microbial Growth

Late log phase of the bacterial growth curve

During which phase of the bacterial growth curve does the total number of viable (live) cells decline?

In the cultivation of microaerophilic and anaerobic bacteria,

Shigella species and Salmonella species are classified as facultative anaerobes. You know that given this information, the bacteria in your patient's fecal culture will grow best

A medium that inhibits the growth of organisms other than the one being sought is called a(n)

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?

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

In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the

During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?

Organisms that use CO2 as their source of carbon are called

Peptone

The solidifying agent used most successfully in bacterial nutrient media is

The prefix photo- indicates that an organism will make use of ________ for energy purposes.

A hot tub (with a water temperature of 104°F or 40°C) would most likely contain

Freezing is an effective means of destroying bacteria.

Clostridium paradoxum grows optimally at 55°C, pH 9.3; it will not grow in the presence of O2. Please select the TRUE statement about this organism.

Prokaryotic cells divide by a process known as

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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