Question 1

How did the antitoxin help the patient?

Accepted Answer

A)   The antitoxin is a mixture of antigens that bind to and thereby neutralize the different serotypes of botulinum toxin.
B)   The antitoxin binds to and destroys Clostridium botulinum cells, preventing them from releasing botulinum toxin.
C)   The antitoxin is a mixture of antibodies that bind to and thereby neutralize the different serotypes of botulinum toxin.
D)   The antitoxin contains antibodies to botulinum toxin type A, which is the type that causes illness.
E)   The antitoxin stimulates phagocytes to neutralize botulinum toxin type A.F) A) and C)
G) A) and D)

Question 2

High concentrations of nucleic acids in the diet may lead to high levels of uric acid in the blood.

Accepted Answer

A) True 
 B)False

Question 3

The tart taste of yogurt, pickles, and sharp cheeses is due to the presence of

Accepted Answer

A)   lactic acid.
B)   acetic acid.
C)   sorbic acid.
D)   benzoic acid.
E)   hydrochloric acid.F) C) and D)
G) A) and B)

Question 4

Sugar is used in the making of fermented sausages to

Accepted Answer

A)   help preserve the sausage.
B)   provide raw material for the fermentation process.
C)   sweeten the taste of spicy sausage.
D)   counteract the action of the salt in the sausage.
E)   remove water from the surface of the meat.F) A) and B)
G) C) and D)

Question 5

Why might the presence of Apsergillus flavus in grain products be a problem?

Accepted Answer

A)   All species of Aspergillus produce aflatoxin, a potent carcinogen.
B)   Some species of Aspergillus produce aflatoxin, a potent carcinogen.
C)   Some species of Aspergillus produce aflatoxin, which kills plants and causes crop loss.
D)   Some species of Aspergillus cause systemic infections in animals that consume them.
E)   Presence of Aspergillus indicates a highly contaminated environment.F) D) and E)
G) A) and B)

Question 6

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

Question 7

Which of the following organisms may grow at pH 3.5?

Accepted Answer

A)   Clostridium AND fungi
B)   Streptococcus AND lactic acid bacteria
C)   fungi AND Streptococcus
D)   fungi AND lactic acid bacteria
E)   lactic acid bacteria AND ClostridiumF) A) and D)
G) A) and E)

Question 8

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.F) All of the above
G) A) and C)

Question 9

Which of the following organisms can grow at a lower water activity than most spoilage bacteria?

Accepted Answer

A)   Pseudomonas species
B)   Staphylococcus aureus
C)   Most yeasts
D)   Streptococcus pyogenes
E)   E. coliF) B) and C)
G) A) and E)

Question 10

Which of the following is most likely to grow at refrigerator temperatures?

Accepted Answer

A)   Mesophiles
B)   Psychrophiles
C)   Thermophiles
D)   Acidophiles
E)   HyperthermophilesF) B) and C)
G) B) and D)

Question 11

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.F) A) and D)
G) C) and E)

Question 12

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

Accepted Answer

A)   Cake
B)   Jam
C)   Syrup
D)   Bread
E)   SteakF) B) and D)
G) B) and C)

Question 13

The bacteria associated with hemolytic uremic syndrome is Escherichia coli O157:H7.

Accepted Answer

A) True 
 B)False

Question 14

Why would the use of a known, reliable starter culture improve the safety of fermented meat products?

Accepted Answer

A)   It doesn't. All fermented meat products are basically unsafe since we can't determine what fermentation products are left behind in the food. Some of them may be toxic.
B)   By using pure starter cultures, we KNOW what we're adding in, and how much. We can control the microbial fermentation precisely to best prepare the food product.
C)   We need to be very careful which microbes are introduced into a food product. Some microbes can interact with microbes already present in the food, producing toxins and toxic byproducts that might harm human beings.
D)   It doesn't. Every fermenting microbe ferments the same way, producing the same products. Whatever we start with, the outcome is the same.
E)   None of these explains why we would use known starter cultures.F) B) and E)
G) C) and E)

Question 15

The water activity in foods that have high levels of salt or sugar is

Accepted Answer

A)   low.
B)   high.
C)   dense.
D)   osmotic.
E)   All of the answer choices are correct.F) A) and B)
G) D) and E)

Question 16

Foodborne intoxication requires the ingestion of living organisms.

Accepted Answer

A) True 
 B)False

Question 17

Naturally occurring antimicrobial chemicals may include

Accepted Answer

A)   benzoic acid.
B)   lysozyme.
C)   allicin.
D)   peroxidase.
E)   All of the choices are correct.F) A) and C)
G) A) and B)

Question 18

On which of the following foods can Staphylococcus aureus multiply with little competition?

Accepted Answer

A)   Bread
B)   Jam
C)   Salty ham
D)   Milk
E)   Bread and jamF) C) and D)
G) B) and E)

Question 19

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

Accepted Answer

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

Question 20

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.F) C) and D)
G) B) and E)

Exam 30: Food Microbiology

Naturally occurring antimicrobial chemicals may include

Correct AnswerverifiedShow Answer

How did the antitoxin help the patient?

Correct AnswerverifiedShow Answer

The water activity in foods that have high levels of salt or sugar is

Correct AnswerverifiedShow Answer

Why might the presence of Apsergillus flavus in grain products be a problem?

Correct AnswerverifiedShow Answer

Which of the following organisms may grow at pH 3.5?

Correct AnswerverifiedShow Answer

Why would the use of a known, reliable starter culture improve the safety of fermented meat products?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

High concentrations of nucleic acids in the diet may lead to high levels of uric acid in the blood.

Correct AnswerverifiedShow Answer

The bacteria associated with hemolytic uremic syndrome is Escherichia coli O157:H7.

Correct AnswerverifiedShow Answer

Which of the following organisms can grow at a lower water activity than most spoilage bacteria?

Correct AnswerverifiedShow Answer

Under what conditions would the patient's stool sample be cultured in order to detect Clostridium botulinum?

Correct AnswerverifiedShow Answer

Which of the following is most likely to grow at refrigerator temperatures?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Most bacteria are inhibited by a pH of

Correct AnswerverifiedShow Answer

The tart taste of yogurt, pickles, and sharp cheeses is due to the presence of

Correct AnswerverifiedShow Answer

On which of the following foods can Staphylococcus aureus multiply with little competition?

Correct AnswerverifiedShow Answer

Foodborne intoxication requires the ingestion of living organisms.

Correct AnswerverifiedShow Answer

Sugar is used in the making of fermented sausages to

Correct AnswerverifiedShow Answer

Lactic acid bacteria

Correct AnswerverifiedShow Answer

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