MCB 100 - QUIZ #9 EXAM 2 QUESTIONS AND
ACCURATE ANSWERS
Place the following statements in the chronological order that best describes the
sequence of events leading to the appearance of acne.
- P. acnes metabolizes glycerol in sebum, forming free fatty acids.
- Overproduction of sebum leads to an accumulation in the follicle.
- Free fatty acids stimulate the release of proinflammatory cytokines within the follicle.
- The blood vessels surrounding the follicle dilate and become more permeable.
- Immune cells such as neutrophils and phagocytes move into the follicle to try to
eliminate P. acnes.
- The buildup of dead cells, bacteria, and body fluids causes a raised pustule to appear
on the skin surface. - Answers - 1. Overproduction of sebum leads to an accumulation
in the follicle.
2. P. acnes metabolizes glycerol in sebum, forming free fatty acids.
3. Free fatty acids stimulate the release of proinflammatory cytokines within the follicle.
4. The blood vessels surrounding the follicle dilate and become more permeable.
5. Immune cells such as neutrophils and phagocytes move into the follicle to try to
eliminate P. acnes.
6. The buildup of dead cells, bacteria, and body fluids causes a raised pustule to appear
on the skin surface.
Which component of a Gram-negative cell wall can cause fever, vasodilation,
inflammation, shock, and blood clotting?
A. Lipid A
B. Peptidoglycan
C. The periplasm
D. The inner membrane - Answers - A
n the case of gastrointestinal disease, how can an intoxication be distinguished from an
infection?
A. An intoxication is usually apparent shortly after ingestion, while an infection takes
longer.
B. Intoxications may be caused by endotoxin.
C. Infections are caused by heat-stable agents.
D. An intoxication usually causes a fever, while an infection does not. - Answers - A
, Most microbes that reside in the intestines are facultative or obligate anaerobes.
Describe the growth of facultative anaerobes in the presence of and also in the absence
of molecular oxygen.
A. Facultative anaerobes require a small amount of molecular oxygen.
B. Facultative anaerobes grow equally well in the presence of and in the absence of
molecular oxygen.
C. Facultative anaerobes can grow without molecular oxygen, but grow faster in its
presence.
D. Facultative anaerobes require the absence of molecular oxygen. - Answers - C
An appropriately stained smear was prepared of a sputum specimen obtained from the
sick woman on Lance's flight. Using oil-immersion magnification on your microscope,
what would you observe that would aid in the diagnosis of tuberculosis?
A. acid-fast cocci
B. Gram-positive cocci
C. acid-fast rods
D. Gram-positive rods - Answers - C
The BCG vaccine is available to immunize people against tuberculosis. Had Lance
been vaccinated, he would not have been concerned about becoming infected on the
airplane. Why was he NOT vaccinated?
A. The vaccine requires repeated booster shots because the immune protection is short
lived.
B. The vaccine provides immune protection only for a low percentage of people.
C. Use of the vaccine in large populations results in the emergence of drug-resistant
strains of Mycobacterium tuberculosis.
D. Immunized patients have a positive skin reaction when tested, even if they have not
been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the
work of epidemiologists trying to track the spread of the disease. - Answers - D
Lance's physician administered a tuberculin test to determine whether Lance had been
infected during his flight from South Africa. How was this test performed?
A. A sputum specimen from Lance was cultured for possible growth of Mycobacterium
tuberculosis.
B. Lance's blood was drawn and examined for the presence of Mycobacterium
tuberculosis.
C. An X-ray film of Lance's lungs was taken.
D. A small amount of cell wall material from Mycobacterium tuberculosis was injected
into Lance's forearm skin. - Answers - D
How is tuberculosis transmitted?
ACCURATE ANSWERS
Place the following statements in the chronological order that best describes the
sequence of events leading to the appearance of acne.
- P. acnes metabolizes glycerol in sebum, forming free fatty acids.
- Overproduction of sebum leads to an accumulation in the follicle.
- Free fatty acids stimulate the release of proinflammatory cytokines within the follicle.
- The blood vessels surrounding the follicle dilate and become more permeable.
- Immune cells such as neutrophils and phagocytes move into the follicle to try to
eliminate P. acnes.
- The buildup of dead cells, bacteria, and body fluids causes a raised pustule to appear
on the skin surface. - Answers - 1. Overproduction of sebum leads to an accumulation
in the follicle.
2. P. acnes metabolizes glycerol in sebum, forming free fatty acids.
3. Free fatty acids stimulate the release of proinflammatory cytokines within the follicle.
4. The blood vessels surrounding the follicle dilate and become more permeable.
5. Immune cells such as neutrophils and phagocytes move into the follicle to try to
eliminate P. acnes.
6. The buildup of dead cells, bacteria, and body fluids causes a raised pustule to appear
on the skin surface.
Which component of a Gram-negative cell wall can cause fever, vasodilation,
inflammation, shock, and blood clotting?
A. Lipid A
B. Peptidoglycan
C. The periplasm
D. The inner membrane - Answers - A
n the case of gastrointestinal disease, how can an intoxication be distinguished from an
infection?
A. An intoxication is usually apparent shortly after ingestion, while an infection takes
longer.
B. Intoxications may be caused by endotoxin.
C. Infections are caused by heat-stable agents.
D. An intoxication usually causes a fever, while an infection does not. - Answers - A
, Most microbes that reside in the intestines are facultative or obligate anaerobes.
Describe the growth of facultative anaerobes in the presence of and also in the absence
of molecular oxygen.
A. Facultative anaerobes require a small amount of molecular oxygen.
B. Facultative anaerobes grow equally well in the presence of and in the absence of
molecular oxygen.
C. Facultative anaerobes can grow without molecular oxygen, but grow faster in its
presence.
D. Facultative anaerobes require the absence of molecular oxygen. - Answers - C
An appropriately stained smear was prepared of a sputum specimen obtained from the
sick woman on Lance's flight. Using oil-immersion magnification on your microscope,
what would you observe that would aid in the diagnosis of tuberculosis?
A. acid-fast cocci
B. Gram-positive cocci
C. acid-fast rods
D. Gram-positive rods - Answers - C
The BCG vaccine is available to immunize people against tuberculosis. Had Lance
been vaccinated, he would not have been concerned about becoming infected on the
airplane. Why was he NOT vaccinated?
A. The vaccine requires repeated booster shots because the immune protection is short
lived.
B. The vaccine provides immune protection only for a low percentage of people.
C. Use of the vaccine in large populations results in the emergence of drug-resistant
strains of Mycobacterium tuberculosis.
D. Immunized patients have a positive skin reaction when tested, even if they have not
been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the
work of epidemiologists trying to track the spread of the disease. - Answers - D
Lance's physician administered a tuberculin test to determine whether Lance had been
infected during his flight from South Africa. How was this test performed?
A. A sputum specimen from Lance was cultured for possible growth of Mycobacterium
tuberculosis.
B. Lance's blood was drawn and examined for the presence of Mycobacterium
tuberculosis.
C. An X-ray film of Lance's lungs was taken.
D. A small amount of cell wall material from Mycobacterium tuberculosis was injected
into Lance's forearm skin. - Answers - D
How is tuberculosis transmitted?
