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Microbiology Exam 3
Terms in this set (200)
is nonspecific and present at birth.
All of the following protect the skin and mucous membranes from infection EXCEPT
Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?
mucociliary escalator intestines
Normal microbiota provide protection from infection in each of the following ways EXCEPT
they produce lysozyme.
A differential cell count is used to determine each of the following EXCEPT
the number of red blood cells
Which of the following statements about fixed macrophages is FALSE?
They develop from neutrophils.
All of the following are true regarding NK cells EXCEPT
they destroy infected body cells by phagocytosis.
Which of the following is involved in resistance to parasitic helminths?
If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers?
Which statement regarding the lymphatic system is true?
Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.
Which of the following is an effect of opsonization?
increased adherence of phagocytes to microorganisms
Neutrophils with defective lysosomes are unable to
produce toxic oxygen products.
After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT
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?
phagocytosis in the inflammatory response
The swelling associated with inflammation decreases when the fluid
goes into lymph capillaries.
All of the following are effects of histamine EXCEPT
Which of the following is mismatched?
chemotaxis chemical degradation inside a phagolysosome
__________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form.
A chill is a sign that
body temperature is rising.
You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________.
dilation of blood vessels
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
Which of the following is found normally in serum?
The antimicrobial effects of AMPs include all of the following EXCEPT
inhibition of phagocytosis.
All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT
they are effective for long periods
The alternative pathway for complement activation is initiated by
lipid-carbohydrate complexes and C3.
The classical pathway for complement activation is initiated by
All of the following are iron-binding proteins found in humans EXCEPT
The lectin pathway for complement action is initiated by
mannose on the surface of microbes.
Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis?
Which of the following statements concerning phagocytosis is true?
Bacteria are digested when the phagosome fuses with a lysosom
Which of these molecules or structures is/are NOT associated with innate immunity?
The epidermis __________.
contains the protein keratin
The ID50 for many pathogens is significantly smaller when testing with gnotobiotic animals compared to animals with normal microbiota. This is likely because of __________.
The respiratory system is protected against harmful microbes by all of the following EXCEPT __________.
the lacrimal apparatus
Which of the following statements about sebum is NOT true?
It raises the pH of skin.
One remarkable finding on a patient's laboratory workup is a marked eosinophilia. This might be suggestive of __________.
either a parasitic infection or an allergic (hypersensitivity) reaction
Which of these structures are NOT part of the mononuclear phagocytic system?
Which answer is NOT true for adherence of a phagocyte to a microbe?
Antibody molecules attached to the microbe will limit adherence.
Which answer is true for bacterial destruction by phagocytosis?
Myeloperoxidase in lysosomes is involved in the formation of HOCl.
The stage of phagocytosis in which the phagocyte's plasma membrane attaches to the surface of the microbe is called __________.
Which answer is NOT true of the inflammatory process?
The area becomes red because of a decrease in capillary diameter.
Which of the following statements is NOT true of inflammation?
Many neutrophils can be found at the site of chronic inflammation.
Activation of the complement cascade __________.
can cause the infecting microbe to be killed by lysis
Complement can be activated by all of the following EXCEPT __________.
the presence of host tissue
Which of the following statements is NOT true of nitric oxide (NO)?
It is of little value in killing microbes or tumor cells.
Assume you mix red blood cells, antibodies against the red blood cells, and complement in a test tube. What would you expect to see?
lysis of the red blood cells
Which of the following statements is NOT true of the classical pathway of complement activation?
C3 is the first component to be activated.
Complement component C3, in the classical pathway, is split by __________.
Which of the following occurs first, setting in motion the remaining events?
Toll-like receptors (TLRs) on macrophages and dendritic cells attach to pathogen-associated microbial patterns (PAMPS) on invading microorganisms.
are host-specific but not virus-specific
Which of the following statements concerning cellular immunity is FALSE?
Cellular immunity involves cells that recognize antigens and make specific antibodies against them.
Which cytokines are believed to contribute to autoimmune disease, such as rheumatoid arthritis?
tumor necrosis factor (TNF)
The specificity of an antibody is due to
the variable portions of the H and L chains.
The antibodies found in mucus, saliva, and tears are
The antibodies that can bind to large parasites are
In addition to IgG, the antibodies that can fix complement are
Large antibodies that agglutinate antigens are
The most abundant class of antibodies in serum is
Which of the following is the best definition of antigen?
a chemical that elicits an antibody response and can combine with these antibodies
The presence of which of the following indicates a current infection rather than a previous infection or vaccination?
An antibody's Fc region can be bound by
Which immunoglobulin class, found in blood, lymph, and the intestine, can cross the placenta and help to protect a fetus?
If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first?
Which of the following is NOT a characteristic of B cells?
They recognize antigens associated with MHC I.
The following events elicit an antibody response. What is the third step?
TH cell recognizes antigen-digest and MHC II.
What is the correct sequence of events for activation of a B cell by a T-dependent antigen?
(1) Immunoglobulin receptors on the B cell recognize and bind the antigen. (2) An antigen fragment in complex with MHC class 2 is displayed on the B cell's surface. (3) The MHC-antigen complex binds a receptor on a TH cell. (4) The TH cell secretes cytokines that activate the B cell.
Which of the following statements is NOT a possible outcome of antigen-antibody reaction?
When an antibody binds to a toxin, the resulting action is referred to as
Which of the following recognizes antigens displayed on host cells with MHC II?
Which of the following WBCs are NOT lymphocytes?
Which of the following destroys virus-infected cells?
Cytokines released by TH1 cells
activate CD8+ cells to CTLs.
IL-2, produced by TH cells,
stimulates TH cell maturation
Which of the following statements concerning antigen-presenting cells is true?
They are involved in activating T cells.
Consider a helminthic infection in which an individual is colonized by a parasitic worm. The worm is too big to be engulfed by a phagocytic cell. How does the immune system respond?
The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it.
Which of the following statements concerning immunological memory is true?
The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure.
What type of immunity results from vaccination?
artificially acquired active immunity
What type of immunity results from transfer of antibodies from one individual to a susceptible individual by means of injection?
artificially acquired passive immunity
What type of immunity results from recovery from mumps?
naturally acquired active immunity
Newborns' immunity due to the transfer of antibodies across the placenta is an example of
naturally acquired passive immunity.
Which of the following results in comparatively long-lasting immunity?
A person survives an infection disease
The resistance to reinfection with measles virus following recovery from measles infection is called __________.
HIV selectively destroys CD4 cells and as a result, a person with AIDS is susceptible to life-threatening viral infections. Knowing this, you can conclude that __________.
these viruses have T-dependent antigens
Cyclosporine is a drug sometimes used to prevent transplant rejection after organ transplant surgery. This drug specifically disrupts cell-mediated immunity by cytotoxic T cells. Which of these events can be predicted based on this information?
Antibody production will NOT be disrupted in the recipient.
Cell-mediated immunity in part protects against __________.
intracellular bacteria and viruses
Which of these cell types is NOT involved in cell-mediated immunity?
Which of the following statements is NOT true of antigens?
They often have a molecular weight of less than 10,000.
The most abundant Ig in the blood serum is __________.
Which of the following statements is NOT of the IgA antibody class?
It can trigger the complement cascade.
Which of the following would be a possible consequence of a disorder that selectively destroys the T regulatory cells in a patient?
Which of the following are NOT antigen-presenting cells ?
helper T cells
Which of these processes is in the proper sequence?
IgE is formed; IgE binds to mast cells and basophils; antigen binds IgE; histamine is released.
Which of these lists is in the correct order of differentiation?
stem cells to B cells to plasma cells
Which of these statements is NOT true of antibody molecules?
Antibody molecules can directly destroy antigens.
A property of T cells, but not B cells, is their __________.
ability to form cells that directly kill virus-infected host cells
Which of the following statements is NOT true for T helper cells?
they lyse target cells
T cytotoxic cells __________.
Which of these answers is a potential concern of using T-independent antigens as vaccines?
These antigens will be ineffective in producing an immune response in infants.
Antibody-dependent cell-mediated cytotoxicity __________.
is particularly important for killing microbes that are too large be destroyed by phagocytosis
Which answer is true of the anamnestic response?
A patient shows the presence of antibodies against diphtheria toxin. Which of the following statements is FALSE?
The patient was near someone who had the disease
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)
nucleic acid vaccine
Toxoid vaccines, such as the vaccines against diphtheria and tetanus, elicit a(n)
antibody response against these bacterial toxins.
Purified protein from Bordetella pertussis is used in a(n)
What type of vaccine is the live, weakened measles virus?
attenuated whole-agent vaccine
A vaccine against HIV proteins made by a genetically-engineered vaccinia virus that has infected a eukaryotic cell line is a(n)
Live weakened polio virus can be used directly in a(n)
attenuated whole-agent vaccine.
Haemophilus capsule polysaccharide plus diphtheria toxoid is a(n)
Dead Bordetella pertussis can be used in a(n)
inactivated whole-agent vaccine.
Which of the following best describes vaccination?
An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures to the pathogen because the adaptive immune system is stimulated to produce memory B cells and memory T cells, which protect from subsequent exposures.
What is an adjuvant?
a chemical additive that increases the effectiveness of vaccines
Patient's serum, influenza virus, and red blood cells are mixed in a tube. What happens if the patient has antibodies against influenza virus?
In an agglutination test, eight serial dilutions to determine antibody titer were set up. Tube #1 contained a 1:2 dilution; tube #2, a 1:4, etc. If tube #6 is the last tube showing agglutination, what is the antibody titer?
A reaction between an antibody and soluble antigen-forming lattices is called a(n)
A reaction between antibody and particulate antigen is called a(n)
A reaction that uses the absence of hemolysis of red blood cells to indicate an antigenantibody reaction is called a(n)
A test used to detect anti-Rickettsia antibodies in a patient's serum is the
indirect fluorescent-antibody test.
Which of the following is a test to determine a patient's blood type by mixing the patient's red blood cells with antisera?
direct agglutination reaction
Which of the following is a pregnancy test used to find the fetal hormone HCG in a woman's urine using anti-HCG and latex spheres?
indirect agglutination reaction
A hybridoma results from the fusion of a(an)
B cell with a myeloma cell.
Which component in the figure came from the patient in this indirect ELISA test?
Monoclonal antibodies are used in diagnostic tests and disease treatments because they
are highly specific and they can be produced in large quantities
Palivizumab is used to treat respiratory syncytial virus disease. This antiviral drug is a(n)
In a direct ELISA test to screen for drugs in a patient's urine, what is the third step in the test process?
enzyme-labeled antibodies against the drug being tested is added
Which item is from the patient in a direct ELISA test?
Which of the following tests is MOST useful in determining the presence of AIDS antibodies?
Which of the following uses fluorescent-labeled antibodies?
In an immunodiffusion test to diagnose the fungal disease histoplasmosis, a patient's serum is placed in a well in an agar plate. In a positive test, a precipitate forms as the serum diffuses from the well and meets material diffusing from a second well. In this test process, what is the most likely identity of the material in the second well?
a purified fungal antigen
Western blotting is best used for which of the following?
to detect a specific protein in a mixture
Direct fluorescent-antibody techniques are frequently used to __________.
detect microorganisms in a clinical sample
As a pediatric oncology nurse, you work with children who are receiving chemotherapy and are frequently immunosuppressed. Which of these types of vaccines are generally NOT appropriate for this patient population?
attenuated whole-agent vaccines
Which of the following statements is NOT true of toxoid vaccines?
Only one dose is generally enough to infer a lasting immune response.
Subunit vaccines tend to be safer than whole-cell vaccines because __________.
they cannot reproduce in the host
Which of these statements is true for conjugated vaccines?
They are useful because infants respond poorly to polysaccharide-based antigens.
The results of a titer for varicella antibodies show that Sarah is nonimmune to varicella virus. She decides to get the varicella vaccine, but her physician will not vaccinate her at this time because she is currently pregnant. Why should this vaccine NOT be given to pregnant women?
There is a risk of the attenuated vaccine strain crossing the placenta and infecting the fetus.
Viral vaccines have been produced using viruses grown by all of these methods EXCEPT __________.
grow on agar plates
Which of these answers describes the best way to diagnose congenital toxoplasmosis in a newborn infant?
Test the infant's serum for the presence of IgM antibodies against Toxoplasma.
Hemagglutination in an immunoassay __________.
involves antibodies cross-linking erythrocytes
The viral hemagglutination inhibition test __________.
can be used to detect the presence of antibody to the measles virus in patient serum
After receiving a tick bite, Jenny worries that she may have become infected with Lyme disease. Her doctor immediately orders a Lyme titer, which comes back as negative. Her doctor advises her to come back in three weeks and have the titer repeated. Why?
The initial titer may have been done so early in the infection that detectable levels of antibody were not yet present.
The toxin neutralization assay __________.
can detect the presence of antitoxin
In an agglutination assay in which serum is diluted by half in each successive well (1:2; 1:4; 1:8; 1:16, etc.), if the 1:64 well is the last well to show agglutination, the titer is __________.
In a complement-fixation test, for a serum sample containing antibody against the target antigen, __________.
complement will be fixed, and sheep red blood cells will not lyse
A patient's serum is tested using the complement fixation test. If hemolysis occurs, __________.
complement was not fixed by antibodies in the patient's serum and was available to the antibodies, thus inducing lysis of sheep red blood cells
To detect the presence of antibody to a pathogen in a person through use of the indirect fluorescent-antibody technique, __________.
a known antigen is fixed to a slide, patient serum is added, and labeled antibodies that are directed against human antibodies are added
For both the direct and the indirect ELISA, __________.
substrate is added as a final step
Monoclonal antibodies do NOT have which of the following properties?
They consist of antibodies that react with many different antigens.
Which of these is NOT a property of the fluorescence-activated cell sorter (FACS)?
It can detect serum antibody levels.
Which of the following statements is NOT true for the indirect ELISA?
An antibody sandwich is created.
Which of these immunological assays for serum antibody requires cells as the indicator?
All of the following are true of hypersensitivity EXCEPT
it occurs when an individual is exposed to an allergen for the first time.
The chemical mediators of anaphylaxis are
found in basophils and mast cells.
Which of the following may result from systemic anaphylaxis?
Which antibodies will be in the serum of a person with blood type B, Rh+?
When testing donated blood for compatibility you would find a person with O type blood
will lack A and B red blood cell antigens.
A positive tuberculin skin test is an example of
delayed cell-mediated immunity.
Allergic contact dermatitis is due to
sensitized T cells.
The process of desensitization to prevent allergies involves the injection of increasing amounts of
Which blood transfusions in the table are incompatible?
Hemolytic disease of the newborn can result from an
Rh- mother with an Rh+ fetus
Anaphylaxis is the term for reactions caused when certain antigens combine with
Symptoms of delayed cell-mediated reactions are due to
Rheumatoid arthritis is due to deposition of
complexes of IgM and IgG and also complement in joints.
Which of the following is FALSE concerning type II (cytotoxic) hypersensitivity reactions?
IgE binds to mast cells or basophils.
Assuming Rh compatibility is present, individuals with which of the following blood types would be able to receive donor blood from any of the four blood types (A, B, AB, and O)?
Which of the following types of transplant is least compatible?
Graft-versus-host disease will most likely be a complication of a(n)
bone marrow transplant.
Treatment with certain drugs to reduce transplant rejection can cause
Which of the following statements about human embryonic stem cells is TRUE?
They are pluripotent and typically obtained from the blastocyst stage of embryonic development.
In the serological method for tissue typing, if human cells expressing HLA-I are mixed with anti-HLA-I, complement, and trypan blue, what would indicate the cells are HLA-I?
Trypan blue enters the cells.
Which of the following utilizes a combination of monoclonal antitumor antibody and immunotoxin?
A healthy immune system destroys cancer cells with
CTLs and activated macrophages.
Which of the following is a xenotransplantation product?
the replacement of a human's heart valve with a pig's heart valve
Which statement regarding cancer immunotherapy is FALSE?
An immunotoxin is an antigen combined with a toxic agent.
Immunodeficiencies are a result of all of the following EXCEPT
Attachment of HIV to the target cell depends on
gp120 combining with the CD4+ receptor.
Worldwide, the primary method of transmission of HIV is
Which of the following is the least likely vaccine against HIV?
Which of the following is a possible outcome of an HIV infection?
All of the answers are correct.
The number of T cells drops to below 200 cells/microliter in which phase of HIV infection?
Which of the following statements is NOT true for type I (anaphylactic) hypersensitivity reactions?
IgG and IgM antibodies are involved.
What type of immunoglobulin binds to mast cells during an allergic reaction?
Which of the following is NOT a case of localized anaphylaxis?
poison ivy rash
Blood transfusion hypersensitivity reactions are examples of __________.
type II (cytotoxic) hypersensitivity
Although maternal-fetal incompatibilities are possible in the ABO blood group, the incidence of adverse reactions in the fetus or newborn is far less common than in the case of Rh incompatibilities. Which of the following is the most likely explanation?
Maternal anti-A and anti-B antibodies typically do not cross the placenta.
Which of the following diseases is a type III autoimmune disease?
A patient with severe burns on her hands and arms has a skin graft with skin taken from her upper thigh. This type of tissue transplant is a/an __________.
Following an organ transplant, therapeutic immunosuppression to prevent organ rejection may be accomplished by any of the following EXCEPT __________.
Which of the following is NOT an example of immunotherapy for cancer treatment or prevention?
HAART for HIV infection
Which type of graft will most likely cause hyperacute rejection?
Which of the following is/are NOT a component of the HIV virion?
HIV can remain latent in the host cell by integrating its reverse-transcriptase-produced DNA into the host chromosome, becoming a/an __________.
All of the following concerning the clinical phases of HIV infection are correct EXCEPT__________.
phase 1: Kaposi's sarcoma
Which of the following could be predicted for an individual with a mutation in the gene encoding CCR5?
resistance to HIV infection
Which of the following predictions can be made regarding the immune responses of individuals with AIDS?
They can make antibody in response to T-independent antigens.
Which of the following diseases is most likely to be similar to AIDS in terms of the specific immunodeficiency?
Which is NOT a mechanism used in anti-HIV drugs?
inhibition of cell-wall synthesis
Which of the following is NOT a common disease associated with AIDS?
The desensitization injections for allergy treatments are aimed at producing __________.
In hemolytic disease of the newborn, fetal red blood cells are targeted for destruction by __________.
maternal IgG antibodies
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