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Microb 230 Test Revision > Exam 4 > Flashcards

Exam 4 Flashcards

1
Q

Innate immunity
* is slower than adaptive immunity in responding to pathogens.
* is nonspecific and present at birth.
* involves a memory component.
* involves T cells and B cells.
* provides increased susceptibility to disease.

A

Innate immunity is nonspecific and present at birth.

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2
Q

Which of the following exhibits the highest phagocytic activity?
* eosinophils
* erythrocytes
* macrophages
* basophils
* neutrophils

A

macrophages

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3
Q

The complement protein cascade is the same for the classical pathway, alternative pathway, and
lectin pathway after the point in the cascade where the activation of ________ takes place.

A

C3

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4
Q

A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding.
Which of the following defense mechanisms will participate in eliminating contaminating
microbes?
* mucociliary escalator
* normal skin flora
* phagocytosis in the inflammatory response
* acidic skin secretions
* lysozyme

A
  • phagocytosis in the inflammatory response
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5
Q

Margination refers to
* the adherence of phagocytes to microorganisms.
* the chemotactic response of phagocytes.
* adherence of phagocytes to the lining of blood vessels.
* dilation of blood vessels.
* the movement of phagocytes through walls of blood vessels.

A
  • adherence of phagocytes to the lining of blood vessels.
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6
Q

Each of the following is an effect of complement activation EXCEPT
* interference with viral replication.
* bacterial cell lysis.
* opsonization.
* increased phagocytic activity.
* increased blood vessel permeability.

A

EXCEPT interference with viral replication.

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7
Q

Which of the following is an effect of opsonization?
* increased adherence of phagocytes to microorganisms
* increased margination of phagocytes
* increased diapedesis of phagocytes
* inflammation
* cytolysis

A

increased adherence of phagocytes to microorganisms

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8
Q

Phagocytes utilize all of the following to optimize interaction with (getting to and getting hold of)
microorganisms EXCEPT
* trapping a bacterium against a rough surface.
* opsonization.
* chemotaxis.
* lysozyme.
* complement.

A

EXCEPT lysozyme

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9
Q

All of the following are effects of histamine EXCEPT
* vasodilation.
* fever.
* swelling.
* redness.
* pain.

A

EXCEPT fever

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10
Q

The classical pathway for complement activation is initiated by
* lipid-carbohydrate complexes and C3.
* C5-C9.
* antigen-antibody reactions.
* factors released from phagocytes.
* factors released from damaged tissues.

A

antigen-antibody reactions

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11
Q

Innate immunity includes all of the following EXCEPT
* phagocytosis.
* inflammation.
* production of antibody.
* production of interferon.
* activation of complement.

A

EXCEPT production of antibody

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12
Q

All of the following are true regarding NK cells EXCEPT
* they are a type of lymphocyte.
* they are found in tissues of the lymphatic system.
* they have the ability to kill infected body cells and some tumor cells.
* they destroy infected body cells by phagocytosis.
* they release toxic substances that cause cell lysis or apoptosis.

A

EXCEPT they destroy infected body cells by phagocytosis.

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13
Q

Which of the following is involved in resistance to parasitic helminths?
* basophils
* eosinophils
* lymphocytes
* monocytes
* neutrophils

A

eosinophils

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14
Q

Macrophages arise from which of the following?
* basophils
* eosinophils
* lymphocytes
* monocytes
* neutrophils

A

monocytes

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15
Q

All of the following occur during inflammation. What is the first step?
* diapedesis
* margination
* phagocyte migration
* repair
* vasodilation

A

vasodilation

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16
Q

Which non-specific defense mechanism is mismatched with its associated body structure or body
fluid?
* lysozyme – tears and saliva
* mucociliary escalator – intestines
* very acidic pH – stomach
* keratin and tightly packed cells – skin
* cerumen and sebum – ear

A

MISMATCHED: mucociliary escalator – intestines

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17
Q

What type of immunity results from vaccination?
* innate immunity
* naturally acquired active immunity
* naturally acquired passive immunity
* artificially acquired active immunity
* artificially acquired passive immunity

A
  • artificially acquired active immunity
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18
Q

What type of immunity results from transfer of antibodies from one individual to a susceptible
individual by means of injection?
* innate immunity
* naturally acquired active immunity
* naturally acquired passive immunity
* artificially acquired active immunity
* artificially acquired passive immunity

A
  • artificially acquired passive immunity
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19
Q

What type of immunity results from recovery from mumps?
* innate immunity
* naturally acquired active immunity
* naturally acquired passive immunity
* artificially acquired active immunity
* artificially acquired passive immunity

A
  • naturally acquired active immunity
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20
Q

Newborns’ immunity due to the transfer of antibodies across the placenta is an example of
* innate immunity.
* naturally acquired active immunity.
* naturally acquired passive immunity.
* artificially acquired active immunity.
* artificially acquired passive immunity.

A
  • naturally acquired passive immunity.
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21
Q

Which of the following cells is NOT an APC?
* dentritic cells
* macrophages
* mature B cells
* natural killer cells

A
  • natural killer cells
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22
Q

CD4+ T cells are activated by:
* interaction between CD4+ and MHC II.
* interaction between TCRs and MHC II.
* cytokines released by dendritic cells.
* cytokines released by B cells.
* complement.

A
  • interaction between CD4+ and MHC II.
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23
Q

Which of the following recognizes antigens displayed on host cells with MHC II?
* TC cell
* B cell
* TH cell
* natural killer cell
* basophil

A
  • TH cell
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24
Q

The specificity of an antibody is due to
* its valence.
* the H chains.
* the L chains.
* the constant portions of the H and L chains.
* the variable portions of the H and L chains.

A
  • the variable portions of the H and L chains.
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25
Q

Which of the following is NOT a characteristic of B cells?
* They originate in bone marrow.
* They have antibodies on their surfaces.
* They are responsible for the memory response.
* They are responsible for antibody formation.
* They recognize antigens associated with MHC I.

A
  • They DO NOT recognize antigens associated with MHC I.
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26
Q

Which of the following is NOT a characteristic of cellular immunity?
* The cells originate in bone marrow.
* Cells mature in the thymus gland.
* Response to abnormal cells.
* B cells make antibodies.
* T cells interact with epitopes in MHC molecules.

A
  • B cells make antibodies.
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27
Q

The most abundant class of antibodies in serum is
* IgG.
* IgM.
* IgA.
* IgD.
* IgE.

A

IgG

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28
Q

Which of the following are NOT lymphocytes?
* cytotoxic T cells
* helper T cells
* NK cells
* M cells
* B cells

A
  • M cells
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29
Q

Which of the following destroys virus-infected cells?
* CTL
* Treg
* TH
* dendritic cells
* B cells

A
  • CTL
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30
Q

Which one of the following causes transmembrane channels in target cells?
* granzymes
* hapten
* IL-1
* IL-2
* perforin

A
  • perforin
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31
Q

Thymic selection
* destroys immature T cells
* destroys B cells that make antibodies against self.
* destroys MHC molecules.
* destroys CD4+ cells that attack self.
* activates B cells.

A
  • destroys immature T cells
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32
Q

In Figure 1, which letter on the graph indicates the patient’s secondary response to a repeated
exposure with the identical antigen?

A

C

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33
Q

In Figure 1, the arrow at time (d) indicates:
* the time of exposure to the same antigen as at time (a).
* the secondary response.
* the primary response.
* exposure to a new antigen.
* the T-cell response.

A

exposure to a new antigen

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34
Q

In what way are semisynthetic penicillins and natural penicillins alike?
* Both are broad spectrum.
* Both are resistant to penicillinase.
* Both are resistant to stomach acids.
* Both are bactericidal.
* Both are based on β-lactam.

A
  • Both are based on β-lactam.
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35
Q

Antimicrobial peptides (AMPs) frequently work by
* inhibiting protein synthesis.
* disrupting the plasma membrane.
* complementary base pairing with DNA.
* inhibiting cell-wall synthesis.
* hydrolyzing peptidoglycan.

A
  • disrupting the plasma membrane.
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36
Q

The antimicrobial drugs with the broadest spectrum of activity are
* aminoglycosides.
* chloramphenicol.
* penicillin G.
* macrolides.
* tetracyclines.

A

tetracyclines

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37
Q

Bacteriostatic is a drug that:
* Kills microbes directly
* Prevents microbes from growing
* Kills only gram-negative bacteria
* Kills only gram-positive bacteria

A
  • Prevents microbes from growing
38
Q

The mode of action of penicillins is:
* Inhibition of protein synthesis
* Injury to plasma membrane
* Inhibition of essential metabolite synthesis
* Inhibition of cell wall synthesis

A
  • Inhibition of cell wall synthesis
39
Q

Penicillinases (or beta-lactamases) are:
* Drugs that cause injury to plasma membrane
* Enzymes that inhibit protein synthesis
* Enzymes that destroy the beta-lactam ring of penicillins
* Drugs that destroy the beta-lactam ring of tetracyclins

A
  • Enzymes that destroy the beta-lactam ring of penicillins
40
Q

What do most anti-fungal drugs target?
* DNA replication
* RNA Transcription
* Cell wall
* Ergosterol synthesis

A
  • Ergosterol synthesis
41
Q

What is the mode of action of sulfonamides?
* Inhibition of protein synthesis
* Injury to plasma membrane
* Inhibition of essential metabolite synthesis
* Inhibition of cell wall synthesis

A
  • Inhibition of essential metabolite synthesis
42
Q

What is the mode of action of interferons?
* Inhibition of protein synthesis
* Injury to plasma membrane
* Inhibition of essential metabolite synthesis
* Inhibition of cell wall synthesis
* Produced by viral-infected cells to inhibit further spread of the infection

A
  • Produced by viral-infected cells to inhibit further spread of the infection
43
Q

By synergism, we understand that:
* The effect of two drugs together is greater than the effect of either alone
* The effect of two drugs together is less than the effect of either alone

A
  • The effect of two drugs together is greater than the effect of either alone
44
Q

Who discovered penicillin?
* Koch
* Ehrlich
* Pasteur
* Fleming

A
  • Fleming
45
Q

Based on the data in Table 1, which is the most potent and lethal toxin?

A

Answer: Botulinum

46
Q

Based on the data in Table 2, which portal of entry is most infectious?

A

Answer: Skin

47
Q

Almost all pathogens attach to host cells by using specific molecules called
* Inclusion bodies
* Genotoxins
* Adhesins
* Siderophores

A

Adhesins

48
Q

The ID50 is
* a measure of pathogenicity.
* the dose that will cause an infection in 50 percent of the test population.
* the dose that will kill some of the test population.
* the dose that will cause an infection in some of the test population.
* the dose that will kill 50 percent of the test population.

A
  • the dose that will cause an infection in 50 percent of the test population.
49
Q

All of the following contribute to a pathogen’s invasiveness EXCEPT
* toxins.
* capsules.
* cell wall components.
* hyaluronidase.
* coagulases.

A

EXCEPT toxins

50
Q

Which of the following statements is FALSE?
* Leukocidins destroy neutrophils.
* Hemolysins lyse red blood cells.
* Hyaluronidase breaks down substances between cells.
* Kinase destroys fibrin clots.
* Coagulase destroys blood clots.

A

FALSE. Coagulase DOES NOT destroy blood clots.

51
Q

A healthcare-associated infection (traditionally known as a nosocomial infection) is
* always present, but is inapparent at the time of hospitalization.
* acquired during the course of hospitalization.
* always caused by medical personnel.
* only a result of surgery.
* always caused by pathogenic bacteria.

A
  • acquired during the course of hospitalization.
52
Q

The major significance of Robert Koch’s work is that
* microorganisms are present in a diseased animal.
* diseases can be transmitted from one animal to another.
* microorganisms can be cultured.
* microorganisms cause disease.
* microorganisms are the result of disease.

A
  • microorganisms cause disease.
53
Q

Which of the following is NOT a verified exception in the use of Koch’s postulates?
* Some diseases have poorly defined etiologies.
* Some pathogens can cause several disease conditions.
* Some human diseases have no other known animal host.
* Some diseases are not caused by microbes.
* Some diseases are noncommunicable.

A
  • Some diseases are noncommunicable.
54
Q

Which of the following definitions is INCORRECT?
* endemic: a disease that is constantly present in a population
* epidemic: a disease that is constantly present across the world
* pandemic: a disease that affects a large number of people in the world in a short time
* sporadic: a disease that affects a population occasionally
* incidence: number of new cases of a disease

A

INCORRECT.
epidemic: a disease that is constantly present across the world

55
Q

Transient microbiota differ from normal microbiota in that transient microbiota
* cause diseases.
* are found in a certain location on the host.
* are always acquired by direct contact.
* are present for a relatively short time.
* never cause disease.

A
  • are present for a relatively short time.
56
Q

A cold transmitted by a facial tissue is an example of
* direct contact.
* droplet transmission.
* fomite.
* vector.
* vehicle transmission.

A
  • fomite.
57
Q

A disease in which the causative agent remains inactive for a time before producing symptoms is
referred to as
* subacute.
* subclinical.
* latent.
* zoonotic.
* acute.

A
  • latent.
58
Q

In Figure 2, when is the prevalence the highest?
* July
* January
* February
* March

A
  • February
59
Q

Scenario 1: There was an outbreak. A laboratory confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies.
Scenario 1 is an example of:
* human reservoirs.
* a zoonosis.
* a nonliving reservoir.
* a vector.
* a focal infection.

A
  • a zoonosis.
60
Q

If a prodromal period exists for a certain disease, it should occur prior to
* incubation.
* illness.
* decline.
* convalescence.

A
  • illness.
61
Q

Biological transmission differs from mechanical transmission in that biological transmission
* occurs when a pathogen is carried on the feet of an insect.
* involves fomites.
* involves reproduction of a pathogen in an arthropod vector prior to transmission.
* requires direct contact.
* works only with noncommunicable diseases.

A
  • involves reproduction of a pathogen in an arthropod vector prior to transmission.
62
Q

The rise in herd immunity amongst a population can be directly attributed to:
* increased use of antibiotics.
* improved handwashing.
* vaccinations.
* antibiotic-resistant microorganisms.
* None of the answers is correct.

A
  • vaccinations.
63
Q

Koch observed Bacillus anthracis multiplying in the blood of cattle. What is the condition
specifically called when bacteria are multiplying in the blood?
* bacteremia
* focal infection
* local infection
* septicemia
* systemic infection

A
  • septicemia
64
Q

Which of the following statements about healthcare-associated infections is FALSE?
* They occur in compromised patients.
* They may be caused by opportunists.
* They may be caused by drug-resistant bacteria.
* They may be caused by normal microbiota.
* The patient was infected before hospitalization.

A

FALSE. The patient was NOT infected before hospitalization.

65
Q

One effect of washing regularly with antibacterial agents is the removal of normal microbiota.
This can result in:
* body odor.
* fewer diseases.
* increased susceptibility to disease.
* normal microbiota returning immediately.
* no bacterial growth because washing removes their food source.

A
  • increased susceptibility to disease.
66
Q

Which of the following statements about biological transmission is FALSE?
* The pathogen reproduces in the vector.
* The pathogen may enter the host in the vector’s feces.
* Houseflies are an important vector.
* The pathogen may be injected by the bite of the vector.
* The pathogen may require the vector as a host.

A

FALSE. Not biological.
* Houseflies are an important vector.

67
Q

The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules
and evade destruction by the host’s antibodies is called
* antigenic variation.
* lysogenic conversion.
* virulence.
* cytopathic effect.
* cytocidal effect.

A
  • antigenic variation.
68
Q

Which is NOT specifically employed by pathogens to avoid destruction by phagocytosis?
* producing a capsule
* possessing ability to replicate within a phagolysosome
* producing superantigens
* possessing ability to remain dormant within a phagocyte
* forming biofilms

A

NOT producing superantigens

69
Q

Which organism in Table 3 most easily causes an infection?
* E. coli O157:H7
* Legionella pneumophila
* Shigella
* Treponema pallidum
* The answer cannot be determined based on the information provided.

A
  • Legionella pneumophila
70
Q

Which of the following is NOT a cytopathic effect of viruses?
* cell death
* host cells fusing to form multinucleated syncytia
* inclusion bodies forming in the cytoplasm or nucleus
* increased cell growth
* toxin production

A
  • toxin production
71
Q

Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What
portal of entry does polio virus use?
* skin only
* parenteral only
* mucous membranes only
* skin and parenteral
* skin, parenteral, and mucous membranes

A
  • mucous membranes only
72
Q

Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages
* give new gene sequences to the host bacteria.
* produce toxins.
* carry plasmids.
* kill the bacteria, causing release of endotoxins.
* kill human cells.

A
  • give new gene sequences to the host bacteria.
73
Q

Which of the following contributes to the virulence of a pathogen?
* numbers of microorganisms that gain access to a host
* evasion of host defenses
* toxin production
* numbers of microorganisms that gain access to a host and evasion of host defenses
* numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production

A
  • numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
74
Q

All of the following are used by bacteria to attach to host cells EXCEPT
* M protein.
* ligands.
* fimbriae.
* capsules.
* A-B toxins.

A

EXCEPT
* A-B toxins.

75
Q

Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented
by
* boiling food prior to consumption.
* administering antibiotics to patients.
* not eating canned food.
* preventing fecal contamination of food.
* filtering food.

A
  • boiling food prior to consumption.
76
Q

Superantigens produce intense immune responses by stimulating lymphocytes to produce
* endotoxins.
* exotoxins.
* cytokines.
* leukocidins.
* interferons.

A
  • cytokines.
77
Q

Siderophores are bacterial proteins that compete with the host’s
* antibodies.
* red blood cells.
* iron-transport proteins.
* white blood cells.
* receptors.

A
  • iron-transport proteins.
78
Q

Endotoxins are
* associated with gram-positive bacteria.
* molecules that bind nerve cells.
* part of the gram-negative cell wall.
* excreted from the cell.
* A-B toxins.

A
  • part of the gram-negative cell wall.
79
Q

Which of the following statements about exotoxins is generally FALSE?
* They are more potent than endotoxins.
* They are composed of proteins.
* They are resistant to heat.
* They have specific methods of action.
* They are produced by gram-positive bacteria.

A

FALSE.
* They are NOT resistant to heat.

80
Q

Cytopathic effects are changes in host cells due to
* viral infections.
* protozoan infections.
* fungal infections.
* bacterial infections.
* helminthic infections.

A
  • viral infections.
81
Q

Substances that are recognized as foreign and provoke immune responses are called
* antibodies
* inducers
* antigens
* infective agents

A
  • antigens
82
Q

All of the following are components of the host immune system EXCEPT
* leukocytes
* phagocytes
* antibodies
* antigens

A

EXCEPT
* antigens

83
Q

Which of the following is a physical barrier in the nonspecific defense of a mammalian host?
* Fever
* Inflammation
* Phagocytosis
* Mucous membranes

A
  • Mucous membranes
84
Q

Lysozyme is an enzyme that lyses ________.
* bacteria
* viruses
* parasites
* fungi

A
  • bacteria
85
Q

CRITICAL THINKING: The inhalation of cigarette smoke and similar pollutants has a gradual
effect on cilia lining the respiratory tract, first causing the beating to slow and eventually stop.
How does this change in cilia most directly impact the resistance mechanisms of the host?
* Both acquired and nonspecific immunity would be lost
* Neither acquired nor nonspecific immunity would be lost
* Acquired immunity due to antibody response would be lost
* Innate host immunity due to mechanical barrier protection would be lost

A
  • Innate host immunity due to mechanical barrier protection would be lost
86
Q

Innate and adaptive immunity differ from one another in that ________.
* innate immunity involves MHC I molecules, whereas adaptive immunity involves MHC II molecules
* innate immunity involves general barriers and mechanisms in effect regardless of the nature of the antigen, whereas adaptive immunity is a targeted response to a specific antigen
* innate immunity involves the B lymphocytes, whereas adaptive immunity involves the T lymphocytes
* innate immunity is a targeted response to a specific antigen, whereas adaptive immunity involves general barriers and mechanisms in effect regardless of the nature of the antigen

A
  • innate immunity involves general barriers and mechanisms in effect regardless of the nature of the antigen, whereas adaptive immunity is a targeted response to a specific antigen
87
Q

A deficiency of T-helper cells would affect both cell-mediated immunity as well as antibody production.
* True
* False

A
  • True
88
Q

All of the following are the result of B-cell maturation and activation EXCEPT ________.
* antibody is produced
* plasma cells are produced
* macrophages are activated
* memory cells are produced

A

EXCEPT
* macrophages are activated

89
Q

Which of the following statements describes how antibody-binding brings about the removal of antigens?
* Antibodies directly lyse cells expressing foreign antigen, thus removing the antigen.
* Antibodies directly hydrolyze antigens, destroying them.
* Antibodies tag antigens for destruction, either via phagocytes or via complement activation.
* Antibodies bind to antigens and hasten their removal through the kidneys.

A
  • Antibodies tag antigens for destruction, either via phagocytes or via complement activation.
90
Q

What type of antibody is produced first after the initial exposure to antigen?

A
  • IgM

Microb 230 Test Revision (4 decks)

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