Micro final Flashcards
Cytopathic effects are changes in host cells due to
viral infections
Focal infections initially start out as
local infections
A DNA plasmid encoding a protein antigen from West Nile virus is injected into muscle c ells of a horse. This is an example of
nucleic acid vaccine
A reactions between an antibody and soluble antigen-forming lattices is called a
precipitation reaction
The clumping of test red blood cells indicates a negative test result (no antibodies against the virus in the patient’s serum) in the
viral hemagglutination inhibition test
All of the following occur during inflammation. What is the first step?
vasodilation
D4+ T cells are activated by
interaction between CD4+ and MHC II
All of the following are reasons why an HIV vaccine has not been developed EXCEPT
vaccines are not effective against viral infections
All of the following are components of the inflammatory process EXCEPT
antibody synthesis
A test used to detest anti-Rickettsia antibodies in a patient’s serum is the
indirect fluorescent antibody test
A positive tuberculin skin test is an example of
delay cell mediated immunity
TLRs attach to all of the following EXCEPT
AMPs
Which of the following recognizes antigens displayed on host cells with MCH II
TH cell
What type of immunity results from vaccination
artifically acquired active immunity
Rheumatoid arthritis is due to deposition of
complexes of IgM and IgG and also complement in joints
All of the following protect the skin and mucous membranes from infection EXCEPT
HCl
Which is true regarding Herceptin therapy
it is used to treat some breast cancer patients
Which of the following exhibits the highest phagocytic activity?
macrophages
The chemical mediators of anaphylaxis are
Found in basophils and mast cells
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of
C3
Which of the following may result from systemic anaphylaxis?
Shock
Which of the following is NOT a characteristic of B cell?
they recognize antigens associated with MHC I
Which of the following statements is FALSE?
Coagulase destroys blood clots
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
A reaction between antibody and particulate antigen is called a
agglutination reaction
Pyelonephritis usually is caused by
Escherichia coli.
The lower respiratory tract is protected by all of the following EXCEPT
competition with the normal flora of the lungs
Clostridium difficile-associated diarrhea is usually preceded by
extended use of antibiotics.
You advise your pregnant friend to give her cat away because she could contract
toxoplasmosis
A patient has the following symptoms: a papule, enlarged lymph nodes. Microscopic examination of the papule reveals nucleated cells in white blood cells. The patient most likely
leishmaniasis
A predisposing factor for infection by Clostridium perfringens is
gangrene
An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks earlier she had visited her grandmother, who had shingles. What infection does the eight-year-old have?
chickenpox
The symptoms of gas gangrene are due to all of the following EXCEPT
endocarditis
Normal microbiota of the adult vagina consist primarily of
Lactobacillus
Which of the following statements about salmonellosis is FALSE?
The mortality rate is high.
Which of the following statements about puerperal sepsis is FALSE?
It is transmitted from mother to fetus
All of the following are normal microbiota of the skin EXCEPT
Streptococcus
Which of the following is NOT primarily a sexually transmitted infection (STI)?
trichomoniasis
he most common reservoir for leptospirosis within the United States is
domestic dogs
Bacterial encephalitis and meningitis are difficult to treat because
many antibiotics cannot penetrate the blood—brain barrier
Members of the group A streptococci (GAS) cause all of the following EXCEPT
epiglottitis
All of the following organisms cause meningitis EXCEPT
Mycobacterium leprae
The symptoms of tetanus are due to
tetanospasmin.
All of the following are true regarding African trypanosomiasis EXCEPT
all subspecies of Trypanosoma brucei have multiple hosts.
All of the following are protective factors of the skin and its secretions EXCEPT
pyocyanin production
Which of the following is directly involved in the initiation of dental caries?
lactic acid
Which of the following statements about Neisseria meningitis is FALSE?
It is a gram-positive anaerobe.
Which of the following is NOT a typical symptom of influenza?
diarrhea
Which of the following is a symptom of brucellosis
undulant fever
Which of the following is NOT true of acne?
It can be treated by eliminating fatty foods from the diet.
Which antibodies will be in the serum of a person with blood type B, Rh+? anti-A, anti-B, anti-Rh anti-A, anti-Rh anti-A anti-B
anti A
The yeast Candida albicans does not normally cause disease because of
Answers: symbiotic bacteria. antagonistic bacteria. parasitic bacteria. commensal bacteria
antagonistic bacteria.
A DNA plasmid encoding a protein antigen from West Nile virus is injected into muscle cells of a horse. This is an example of a(n)
Answers: subunit vaccine conjugated vaccine nucleic acid vaccine attenuated whole-agent vaccine
nucleic acid vaccine
Which of the following is an effect of opsonization?
Answers: increased adherence of phagocytes to microorganisms increased margination of phagocytes increased diapedesis of phagocytes inflammation
Selected Answer:
Correct
increased adherence of phagocytes to microorganisms
Which of the following statements about M protein is FALSE?
Answers: It is found on Streptococcus pyogenes. It is found on fimbriae. It is heat- and acid-resistant. It is readily digested by phagocytes
Selected Answer:
Correct
It is readily digested by phagocytes
All of the following are true of hypersensitivity EXCEPT
Answers: it occurs in the presence of an antigen it is synonymous with allergy it occurs when an individual is exposed to an allergen for the first time it is due to an altered immune response
Selected Answer:
Correct
it occurs when an individual is exposed to an allergen for the first time
A reaction between antibody and particulate antigen is called a(n)
Answers: precipitation reaction complement fixation agglutination reactions immunofluerescence
Selected Answer:
Correct
agglutination reactions
All of the following are generally used in vaccines EXCEPT
Answers: antibodies toxoids parts of bacterial cells inactivated viruses
Selected Answer:
Correct
antibodies
Which of the following may result from systemic anaphylaxis?
Answers: hay fever asthma hives shock
Selected Answer:
Correct
shock
An ELISA for Hepatitis C has 95 percent sensitivity and 90 percent specificity. This means that the test
Answers:
detects 95 percent of the true positive samples and has 10 percent false positive results.
detects 5 percent of the true positive samples and has 90 percent false positive results.
detects 90 percent of the true positive samples and has 5 percent false positive results.
detects 95 percent of the true positive samples and has 90 percent false positive results.
Selected Answer:
Correct
detects 95 percent of the true positive samples and has 10 percent false positive results.
Large antibodies that agglutinate antigens are
Answers: IgG IgM IgA IgD
Selected Answer:
Correct
IgM
Which of the following are sources of antibodies for serological testing?
Answers: vaccinated animals monoclonal antibodies viral cultures vaccinated animals and monoclonal antibodies
Selected Answer:
Correct
vaccinated animals and monoclonal antibodies
Which of the following is NOT a characteristic of B cells?
Answers: They originate in bone marrow. They have antibodies on their surfaces. They recognize antigens associated with MHC I. They recognize vaccinated cultures
Selected Answer:
Correct
They recognize antigens associated with MHC I.
A patient shows the presence of antibodies against diphtheria toxin. Which of the following statements is FALSE?
Answers:
The patient may have the disease.
The patient may have had the disease and has recovered.
The patient may have been vaccinated.
The patient was near someone who had the disease.
Selected Answer:
Correct
The patient was near someone who had the disease.
Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?
Answers: bacteremia focal infection local infection septicema
Selected Answer:
Correct
septicema
What type of immunity results from vaccination?
Answers:
innate immunity
naturally acquired active immunity
naturally acquired passive immunity
artificially acquired active immunity
Selected Answer:
Correct
artificially acquired active immunity
The most frequently used portal of entry for pathogens is the
Answers:
mucous membranes of the gastrointestinal tract.
skin
parenteral route
mucous membranes of the respiratory tract.
Selected Answer:
Correct
mucous membranes of the respiratory tract.
Biological transmission differs from mechanical transmission in that biological transmission
Answers: requires an arthropod involves fomites involves specific dieases requires direct contact
involves specific dieases
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?
Answers:
mucociliary escalator
normal skin flora
phagocytosis in the inflammatory response
acidic skin secretions
Selected Answer:
Correct
phagocytosis in the inflammatory response
The chemical mediators of anaphylaxis are
Answers: found in basophils and mast cells antibodies antigens antigen-antibody complexes
Selected Answer:
Correct
found in basophils and mast cells
Plasma cells are activated by a(n)
Answers: antigen T cell B cell memory cell
Selected Answer:
Correct
antigen
The antibodies found in mucus, saliva, and tears are
Answers: IgG IgM IgA IgE
Selected Answer:
Correct
IgA
Innate immunity
Answers: 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
Selected Answer:
Correct
is nonspecific and present at birth.
The clumping of test cells indicates a negative test result in the
Answers:
direct agglutination test
viral hemagglutination inhibition test.
indirect agglutination test
precipitation test
Selected Answer:
Correct
viral hemagglutination inhibition test.
Margination refers to
Answers:
the adherence of phagocytes to microorganisms.
adherence of phagocytes to the lining of blood vessels.
the chemotactic response of phagocytes.
the movement of phagocytes through walls of blood vessels.
Selected Answer:
Correct
adherence of phagocytes to the lining of blood vessels.
Toxoid vaccines, such as the vaccines against diphtheria and tetanus, elicit a(n)
Answers: immune complex dendritic cell proliferation Tc cell response antibody response against these bacterial toxins.
Selected Answer:
Correct
antibody response against these bacterial toxins.
Siderophores are bacterial proteins that compete with the host’s
Answers: antibodies red blood cells iron-transport proteins white blood cells
Selected Answer:
Correct
iron-transport proteins
A reaction between an antibody and soluble antigen-forming lattices is called a(n)
Answers: precipitation reaction agglutination reaction complement fixation neutralization reaction
Selected Answer:
Correct
precipitation reaction
Symptoms of disease differ from signs of disease in that symptoms
Answers: are changes felt by the patient. are changes observed by the physician are specific for a particular disease always occur as part of a syndrome.
Selected Answer:
Correct
are changes felt by the patient.
Twenty-five people developed symptoms of nausea, vomiting, and diarrhea three to six hours after attending a church picnic where they ate a ham and green bean casserole with cream sauce. The most likely cause of this case of food intoxication is
Answers:
botulinum toxin.
aflatoxin.
staphylococcal enterotoxin.
erythrogenic toxin.
Selected Answer:
Correct
erythrogenic toxin.
A positive tuberculin skin test is an example of
Answers: delayed cell-mediated immunity autoimmunity acute contact dermatitis psoriasis
Selected Answer:
Correct
delayed cell-mediated immunity
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of
Answers: C1 C2 C3 C4
Selected Answer:
Correct
C3
Siderophores are bacterial proteins that compete with the host’s
Answers: antibodies RBCs iron-transport proteins WBSc
Selected Answer:
Correct
iron-transport proteins
Which of the following WBCs are NOT lymphocytes?
Answers: cytotoxic T cells helper T cells NK cells M cells
Selected Answer:
Correct
M cells
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as
Answers: subacute subclinical latent zoonotic
Selected Answer:
Correct
latent
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
Answers: antigenic variation. lysogenic conversion virulence. cytopathic effect.
Selected Answer:
Correct
antigenic variation.
The most frequently used portal of entry for pathogens is the
Answers:
mucous membranes of the respiratory tract.
mucous membranes of the gastrointestinal tract.
skin
parenteral route
Selected Answer:
Correct
mucous membranes of the respiratory tract.
Which of the following is NOT a characteristic of cellular immunity?
Answers:
The cells originate in bone marrow.
Cells are processed in the thymus gland.
It can inhibit the immune response
B cells make antibodies.
Selected Answer:
Correct
B cells make antibodies.
The chemical mediators of anaphylaxis are
Answers: found in basophils and mast cells antibodies antigens antigen-antibody complexes
Selected Answers:
Correct
found in basophils and mast cellsq
Margination refers to
Answers:
the adherence of phagocytes to microorganisms
the chemotactic response of phagocytes.
adherence of phagocytes to the lining of blood vessels.
dilation of blood vessels
Selected Answer:
Correct
adherence of phagocytes to the lining of blood vessels.
A Treg cell deficiency could result in
Answers: increased number of viral infections increased number of bacterial infections autoimmunity. increased severity of bacterial infections.
Selected Answer:
Correct
autoimmunity.
In which of the following patterns of disease does the patient experience no signs or symptoms?
Answers: prodromal incubation and convalescence decline incubation
Selected Answer:
Correct
incubation and convalescence
Which of the following recognizes antigens displayed on host cells with MHC II?
Answers: TC cell B cell TH cell natural killer cell
Selected Answer:
Correct
TH cell
Which of the following statements about natural killer cells is FALSE?
Answers: They destroy virus-infected cells They destroy tumor cells. They destroy cells lacking MHC They are stimulated by an antigen.
Selected Answer:
Correct
They are stimulated by an antigen.
An antibody’s Fc region can be bound by
Answers: antibodies macrophages T helper cells B cells
Selected Answer:
Correct
macrophages
The major significance of Robert Koch’s work is that
Answers:
microorganisms are present in a diseased animal.
diseases can be transmitted from one animal to another
microorganisms can be cultured.
microorganisms cause disease.
Selected Answer:
Correct
microorganisms cause disease.
Which of the following statements is FALSE?
Answers:
Leukocidins destroy neutrophils.
Hemolysins lyse red blood cells
Hyaluronidase breaks down substances between cells.
Coagulase destroys blood clots.
Selected Answer:
Correct
Coagulase destroys blood clots.
The following events occur in cellular immunity. What is the third step?
Answers: TH cells proliferate. TH cell produces cytokines. Dendritic cell takes up antigen. Antibodies are produced
Selected Answer:
Correct
TH cells proliferate.
Innate immunity
Answers:
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.
Selected Answer:
Correct
is nonspecific and present at birth
In which of the following diseases can gender be considered a viable predisposing factor?
Answers: urinary tract infections pneumonia salmonellosis tetanus
Selected Answer:
Correct
urinary tract infections
The ID50 is
Answers:
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.
Selected Answer:
Correct
the dose that will cause an infection in 50 percent of the test population.
Which of the following is NOT an example of microbial antagonism?
Answers:
acid production by bacteria
bacteriocin production
bacteria occupying host receptors
bacteria causing disease
Selected Answer:
Correct
bacteria causing disease
Which of the following is NOT a membrane-disrupting toxin?
Answers: streptolysin S hemolysin A-B toxin streptolysin O
Selected Answer:
Correct
A-B toxin
IL-2, produced by TH cells,
Answers: activates macrophages stimulates TH cell maturation. causes phagocytosis activates antigen-presenting cells.
Selected Answer:
Correct
stimulates TH cell maturation.
CD4+ T cells are activated by
Answers:
cytokines released by B cells.
cytokines released by dendritic cells
interaction between CD4+ and MHC II.
interaction between TCRs and MHC II.
Selected Answer:
Correct
interaction between CD4+ and MHC II.
The yeast Candida albicans does not normally cause disease because of
Answers: symbiotic bacteria antagonistic bacteria parasitic bacteria commensal bacteria
Correct
antagonistic bacteria
Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe?
Answers: deficiency of C8 deficiency of C6 deficiency C5 deficiency C3
Correct
deficiency C3
Which of the following may result from systemic anaphylaxis?
Answers: hay fever asthma shock hives
Correct
shock
All of the following contribute to a pathogen’s invasiveness EXCEPT
Answers: toxins capsules cell wall components hyaluronidase
Correct
toxins
The lectin pathway for complement action is initiated by
Answers:
mannose on host membranes.
mannose on the surface of microbes.
lectins of the microbe.
gram-negative cell walls
mannose on the surface of microbes.
All of the following protect the skin and mucous membranes from infection EXCEPT
Answers: multiple layers of cells tears saliva HCL
Correct
HCL
Which of the following statements is TRUE?
Answers:
All three types of interferons have the same effect on the body.
Alpha interferon promotes phagocytosis.
Gamma interferon causes bactericidal activity by macrophages.
Alpha interferon acts against specific viruses.
Correct
Gamma interferon causes bactericidal activity by macrophages.
Which of the following is found normally in serum?
Answers: complement interferon histamine TLRs
Correct
complement
Most pathogens that gain access through the skin
Answers:
can penetrate intact skin
just infect the skin itself
enter through hair follicles and sweat ducts.
must adhere first while their invasive factors allow them to penetrate.
Correct
enter through hair follicles and sweat ducts.
Each of the following is an effect of complement activation EXCEPT
Answers: interference with viral replication bacterial cell lysis opsonization increased phagocytic activtiy
Correct
interference with viral
The function of the “ciliary escalator” is to
Answers:
propel inhaled dust and microorganisms toward the throat.
trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory
remove microorganisms from the lower respiratory tract
remove microorganisms from the upper respiratory tract.
Correct
trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory
When an antibody binds to a toxin, the resulting action is referred to as
Answers: neutralization. agglutination opsonization apoptosis
Correct
neutralization.
Which of the following statements about the classical pathway of complement activation is FALSE?
C1 is the first protein activated in the classical pathway.
The C1 protein complex is initiated by antigenantibody complexes.
C3 is not involved in the classical pathway.
Cleaved fragments of some of the proteins act to increase inflammation.
Correct
C3 is not involved in the classical pathway.
Superantigens produce intense immune responses by stimulating lymphocytes to produce
Answers: endotoxins exotoxins cytokines leukocidins
Correct
cytokines
All of the following are true of hypersensitivity EXCEPT
Answers:
it occurs in the presence of an antigen
its is synonymous with “allergy”
it occurs when an individual is exposed to an allergen for the first time
it is due to an altered immune response
Correct
it occurs when an individual is exposed to an allergen for the first time