Question 1

Which of the following foods has the greatest amount of available water?

Accepted Answer

A)  Cake 
B)  Jam 
C)  Syrup 
D)  Bread 
E)  Steak 
A)  Cake 
B)  Jam 
C)  Syrup 
D)  Bread 
E)  Steak E

Question 2

The malolactic fermentation of wine is performed by

Accepted Answer

A)  Lactobacillus species. 
B)  Saccharomyces species. 
C)  Leuconostoc species. 
D)  Aspergillus species. 
E)  acetic acid bacteria. 
A)  Lactobacillus species. 
B)  Saccharomyces species. 
C)  Leuconostoc species. 
D)  Aspergillus species. 
E)  acetic acid bacteria. C

Question 3

Which of the following is not an intrinsic factor affecting growth of microorganisms on food?

Accepted Answer

A)  Water availability 
B)  Benzoic acid 
C)  Lysozyme 
D)  Temperature 
E)  Fruit rinds 
A)  Water availability 
B)  Benzoic acid 
C)  Lysozyme 
D)  Temperature 
E)  Fruit rinds D

Question 4

Which of the following does NOT produce lactic acid?

Accepted Answer

A)  Lactobacillus 
B)  Leuconostoc 
C)  Streptococcus 
D)  Lactococcus 
E)  Escherichia 
A)  Lactobacillus 
B)  Leuconostoc 
C)  Streptococcus 
D)  Lactococcus 
E)  Escherichia

Question 5

Most large cities have required the pasteurization of milk and milk products since ________.

Accepted Answer

A)  1800 
B)  1850 
C)  1900 
D)  1920 
E)  1985 
A)  1800 
B)  1850 
C)  1900 
D)  1920 
E)  1985

Question 6

The connection between unpasteurized milk and brucellosis in humans was made by

Accepted Answer

A)  Evans. 
B)  Pasteur. 
C)  Koch. 
D)  Fleming. 
E)  Ehrlich. 
A)  Evans. 
B)  Pasteur. 
C)  Koch. 
D)  Fleming. 
E)  Ehrlich.

Question 7

Most human pathogens grow best at temperatures near

Accepted Answer

A)  20ºC. 
B)  25ºC. 
C)  37ºC. 
D)  45ºC. 
E)  97ºF. 
A)  20ºC. 
B)  25ºC. 
C)  37ºC. 
D)  45ºC. 
E)  97ºF.

Question 8

The bacteria associated with hemolytic uremic syndrome is

Accepted Answer

A)  Salmonella cholerasuis. 
B)  Campylobacter jejuni. 
C)  Pseudomonas aeruginosa. 
D)  Escherichia coli O157:H7. 
E)  Lactobacillus. 
A)  Salmonella cholerasuis. 
B)  Campylobacter jejuni. 
C)  Pseudomonas aeruginosa. 
D)  Escherichia coli O157:H7. 
E)  Lactobacillus.

Question 9

Slow cooking for a long time and then storage at room temperature would tend to favor the growth of

Accepted Answer

A)  endospore-formers AND thermophiles. 
B)  endospore-formers AND mesophiles. 
C)  anaerobes AND endospore-formers. 
D)  mesophiles AND thermophiles. 
E)  thermophiles AND anaerobes. 
A)  endospore-formers AND thermophiles. 
B)  endospore-formers AND mesophiles. 
C)  anaerobes AND endospore-formers. 
D)  mesophiles AND thermophiles. 
E)  thermophiles AND anaerobes.

Question 10

Most bacteria are inhibited by a pH of

Accepted Answer

A)  7.2. 
B)  7.0. 
C)  6.0. 
D)  4.5. 
E)  6.5. 
A)  7.2. 
B)  7.0. 
C)  6.0. 
D)  4.5. 
E)  6.5.

Question 11

Why do bacteria generally predominate on fresh meats?

Accepted Answer

A)  Fresh meat provides a moist, acidic, salty, nutrient-rich environment. 
B)  Most bacteria obtain iron from red blood cells-these are abundant in meat. 
C)  Fresh meat provides a moist, pH-neutral, nutrient-rich environment. 
D)  Fresh meat provides a somewhat dry, pH-neutral, saline environment that bacteria prefer. 
E)  The preservatives found on fresh meat stimulate the growth of bacteria. 
A)  Fresh meat provides a moist, acidic, salty, nutrient-rich environment. 
B)  Most bacteria obtain iron from red blood cells-these are abundant in meat. 
C)  Fresh meat provides a moist, pH-neutral, nutrient-rich environment. 
D)  Fresh meat provides a somewhat dry, pH-neutral, saline environment that bacteria prefer. 
E)  The preservatives found on fresh meat stimulate the growth of bacteria.

Question 12

Lactobacillus acidophilus can potentially colonize the intestinal tract.

Accepted Answer

A) True 
 B)False

Question 13

What is the difference between fermented food and spoiled food?

Accepted Answer

A)  Fermented foods are made using certain genera of bacteria only. Spoilage of food involves bacteria, molds, AND yeasts. 
B)  Fermented foods are changed by microbes but are edible. Spoiled foods are also changed by microbes but are full of microbial toxins that always lead to illness. 
C)  Fermented foods may change in appearance but they taste the same as non-fermented foods. Spoiled foods look the same as unspoiled foods but they taste different. 
D)  Fermented foods are intentionally altered during production by carefully controlling the activity of bacteria, yeasts, or molds. Spoiled foods have microbe-induced changes that are undesirable. 
E)  Fermented foods result from undesirable changes made by microbes. Spoiled foods result from desirable changes made by the same types of microbes. 
A)  Fermented foods are made using certain genera of bacteria only. Spoilage of food involves bacteria, molds, AND yeasts. 
B)  Fermented foods are changed by microbes but are edible. Spoiled foods are also changed by microbes but are full of microbial toxins that always lead to illness. 
C)  Fermented foods may change in appearance but they taste the same as non-fermented foods. Spoiled foods look the same as unspoiled foods but they taste different. 
D)  Fermented foods are intentionally altered during production by carefully controlling the activity of bacteria, yeasts, or molds. Spoiled foods have microbe-induced changes that are undesirable. 
E)  Fermented foods result from undesirable changes made by microbes. Spoiled foods result from desirable changes made by the same types of microbes.

Question 14

Limiting the activity of microbes in food can be accomplished by

Accepted Answer

A)  pasteurization. 
B)  cold storage. 
C)  lowering the pH. 
D)  growth inhibiting substances. 
E)  All of the choices are correct. 
A)  pasteurization. 
B)  cold storage. 
C)  lowering the pH. 
D)  growth inhibiting substances. 
E)  All of the choices are correct.

Question 15

A stool sample from the patient is cultured, and confirms the presence of Clostridium botulinum. In addition, the stool sample as well as leftover stew and green beans are tested for botulinum toxin—toxin is present in the green beans and in the stool sample, but not in the stew. These results confirm the diagnosis of foodborne botulism. You are one of the RNs taking care of the patient—he remains in the hospital for several weeks, before being discharged.
-Under what conditions would the patient's stool sample be cultured in order to detect Clostridium botulinum?

Accepted Answer

A)  Anaerobic, body temperature, neutral pH 
B)  Aerobic, body temperature, neutral pH 
C)  Anaerobic, refrigerator temperature, low acidity 
D)  Aerobic, refrigerator temperature, high acidity 
E)  Aerobic or anaerobic, body temperature, low acidity 
A)  Anaerobic, body temperature, neutral pH 
B)  Aerobic, body temperature, neutral pH 
C)  Anaerobic, refrigerator temperature, low acidity 
D)  Aerobic, refrigerator temperature, high acidity 
E)  Aerobic or anaerobic, body temperature, low acidity

Question 16

The water activity in foods with high levels of salt or sugar is high.

Accepted Answer

A) True 
 B)False

Question 17

A stool sample from the patient is cultured, and confirms the presence of Clostridium botulinum. In addition, the stool sample as well as leftover stew and green beans are tested for botulinum toxin—toxin is present in the green beans and in the stool sample, but not in the stew. These results confirm the diagnosis of foodborne botulism. You are one of the RNs taking care of the patient—he remains in the hospital for several weeks, before being discharged.
-Why is botulism primarily a problem in canned foods rather than fresh ones?

Accepted Answer

A)  Canned food is never sterilized, so bacteria such as C. botulinum thrive in cans. 
B)  Fresh food contains normal microbiota that prevents the growth of pathogens such as C. botulinum. 
C)  The canning process dramatically reduces the pH of food, and C. botulinum is an acidophile. 
D)  The causative agent is an obligate anaerobe-the canning process removes O₂. 
E)  All of the answer choices are correct. 
A)  Canned food is never sterilized, so bacteria such as C. botulinum thrive in cans. 
B)  Fresh food contains normal microbiota that prevents the growth of pathogens such as C. botulinum. 
C)  The canning process dramatically reduces the pH of food, and C. botulinum is an acidophile. 
D)  The causative agent is an obligate anaerobe-the canning process removes O₂. 
E)  All of the answer choices are correct.

Question 18

A stool sample from the patient is cultured, and confirms the presence of Clostridium botulinum. In addition, the stool sample as well as leftover stew and green beans are tested for botulinum toxin—toxin is present in the green beans and in the stool sample, but not in the stew. These results confirm the diagnosis of foodborne botulism. You are one of the RNs taking care of the patient—he remains in the hospital for several weeks, before being discharged.
-Why would the home-canned green beans rather than the tomato-beef stew be a possible source of C. botulinum?

Accepted Answer

A)  Beans are low-acid. Any C. botulinum endospores that survived the home-canning process could germinate in the cans, giving rise to vegetative cells that produce botulinum toxin. 
B)  Canning creates an anaerobic environment. Any spores surviving the canning process could germinate, giving rise to vegetative cells that produce botulinum toxin. 
C)  The acidic pH of the tomato-beef stew would likely inhibit that growth of vegetative Clostridium botulinum cells. Low-acidity beans would not inhibit the growth of these cells. 
D)  The tomato-beef stew was not canned. The presence of oxygen in this food would prevent the growth of Clostridium botulinum, which is a obligate anaerobe. 
E)  All of the answer choices are correct. 
A)  Beans are low-acid. Any C. botulinum endospores that survived the home-canning process could germinate in the cans, giving rise to vegetative cells that produce botulinum toxin. 
B)  Canning creates an anaerobic environment. Any spores surviving the canning process could germinate, giving rise to vegetative cells that produce botulinum toxin. 
C)  The acidic pH of the tomato-beef stew would likely inhibit that growth of vegetative Clostridium botulinum cells. Low-acidity beans would not inhibit the growth of these cells. 
D)  The tomato-beef stew was not canned. The presence of oxygen in this food would prevent the growth of Clostridium botulinum, which is a obligate anaerobe. 
E)  All of the answer choices are correct.

Question 19

Lactic acid bacteria

Accepted Answer

A)  consume lactic acid, allowing them to grow on foods such as yogurt. 
B)  produce lactic acid, allowing them to produce foods such as yogurt. 
C)  are important spoilage organisms AND consume lactic acid, allowing them to grow on foods such as yogurt. 
D)  can grow on lemons, are important spoilage organisms, AND consume lactic acid, allowing them to grow on foods such as yogurt. 
E)  produce lactic acid, allowing them to produce foods such as yogurt AND are important spoilage organisms. 
A)  consume lactic acid, allowing them to grow on foods such as yogurt. 
B)  produce lactic acid, allowing them to produce foods such as yogurt. 
C)  are important spoilage organisms AND consume lactic acid, allowing them to grow on foods such as yogurt. 
D)  can grow on lemons, are important spoilage organisms, AND consume lactic acid, allowing them to grow on foods such as yogurt. 
E)  produce lactic acid, allowing them to produce foods such as yogurt AND are important spoilage organisms.

Question 20

Which statement regarding canning and pasteurization is True?

Accepted Answer

A)  Pasteurization uses a process that destroys all microorganisms that can grow under normal storage conditions; the resulting product is commercially sterile. Canning significantly decreases the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain. 
B)  Canning and pasteurization both significantly decrease the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain. 
C)  Canning and pasteurization both use a process that destroys all microorganisms that can grow under normal storage conditions; the resulting products are commercially sterile. 
D)  Canning and pasteurization are essentially the same process-one is used on fresh food while the other is used on preserved food; both result in sterilization of the product. 
E)  Canning uses a process that destroys all microorganisms that can grow under normal storage conditions; the resulting product is commercially sterile. Pasteurization significantly decreases the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain. 
A)  Pasteurization uses a process that destroys all microorganisms that can grow under normal storage conditions; the resulting product is commercially sterile. Canning significantly decreases the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain. 
B)  Canning and pasteurization both significantly decrease the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain. 
C)  Canning and pasteurization both use a process that destroys all microorganisms that can grow under normal storage conditions; the resulting products are commercially sterile. 
D)  Canning and pasteurization are essentially the same process-one is used on fresh food while the other is used on preserved food; both result in sterilization of the product. 
E)  Canning uses a process that destroys all microorganisms that can grow under normal storage conditions; the resulting product is commercially sterile. Pasteurization significantly decreases the number of spoilage microbes and eliminates pathogens; however, viable organisms still remain.

Exam 30: Food Microbiology

Which of the following foods has the greatest amount of available water?

The malolactic fermentation of wine is performed by

Which of the following is not an intrinsic factor affecting growth of microorganisms on food?

Which of the following does NOT produce lactic acid?

Most large cities have required the pasteurization of milk and milk products since ________.

The connection between unpasteurized milk and brucellosis in humans was made by

Most human pathogens grow best at temperatures near

The bacteria associated with hemolytic uremic syndrome is

Slow cooking for a long time and then storage at room temperature would tend to favor the growth of

Most bacteria are inhibited by a pH of

Why do bacteria generally predominate on fresh meats?

Lactobacillus acidophilus can potentially colonize the intestinal tract.

What is the difference between fermented food and spoiled food?

Limiting the activity of microbes in food can be accomplished by

The water activity in foods with high levels of salt or sugar is high.

Lactic acid bacteria

Which statement regarding canning and pasteurization is True?

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

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

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