The condition called parasitism is characterized as a(n)

1) relationship between two organisms where both members benefit.

2) unsuccessful microbial invasion due to the presence of preexisting microbes.

3) relationship between two organisms where only one member benefits and the other is unharmed.

4) nonsymbiotic relationship.

5) relationship between two organisms where one member harms the other.

5) relationship between two organisms were one member harms the other

Commensalism is best described as a(n)

1) unsuccessful microbial invasion due to the presence of preexisting microbes.

2) relationship between two organisms where only one member benefits and the other is unharmed.

3) source of contamination.

4) relationship in which a microorganism causes disease.

5) relationship between two organisms where both members benefit.

2) relationship between two organisms where only one member benefits and the other is unharmed.

A new influenza strain appears and is spreading rapidly. What measures might be taken by public health agencies to stop the spread?

1) Educate the public, promote vaccination, and treat those who are infected.

2) Facilitate access to vaccines.

3) Educate members of the public about ways to protect themselves.

4) Shut down public transportation.

5) Identify and treat people who are infected.

1) Educate the public, promote vaccination, and treat those who are infected.

People who wash their hands frequently during cold season typically have fewer colds than those who do not. This observation suggests cold viruses can be transmitted by

1) direct contact.

2) mechanical vectors.

3) fomites.

4) biological vectors.

5) both direct contact and fomites.

5) both direct contact and fomites.

Which of the following is the CORRECT sequence of a disease process?

1) prodromal period, convalescence, incubation, illness, decline

2) convalescence, incubation, prodromal period, illness, decline

3) illness, convalescence, incubation, prodromal period, decline

4) incubation, prodromal period, illness, decline, convalescence

5) incubation, convalescence, prodromal period, illness, decline

4) incubation, prodromal period, illness, decline, convalescence

Which of the following diseases may be reduced by improved public sanitation measures?

1) malaria

2) rabies

3) chickenpox

4) cholera

5) HIV

4) cholera

Aerosols may be involved in ________ transmission of pathogens.

1) direct

2) droplet

3) fecal-oral

4) waterborne

5) vector

2) droplet

The person known to history as "Typhoid Mary" never had typhoid fever but was identified by public health officials as a source of Salmonella enterica Typhi. Which of the following is the most accurate description of her in this scenario?

1) contact carrier

2) reservoir

3) human carrier

4) both a human carrier and a reservoir

5) a reservoir but not a carrier

4) both a human carrier and a reservoir

Over 470,000 cases of cholera were reported in Haiti in the two years following the 2010 earthquake. Which of the following was the most likely mode of transmission?

1) mosquitoes

2) aerosols

3) contaminated milk

4) contact

5) contaminated water

5) contaminated water

A person is exposed to rotten wood with fungal growth and develops blastomycosis. No one taking care of him/her becomes ill. Blastomycosis is an example of a ________ disease.

1) subacute

2) noncommunicable

3) contagious

4) chronic

5) latent

2) noncommunicable

Diseases that are induced by modern medical procedures are referred to as ________ infections.

1) endogenous

2) opportunistic

3) subacute

4) iatrogenic

5) exogenous

4) iatrogenic

Which of the following stages of an infectious disease is the most severe?

1) the illness period

2)the prodromal period

3) the convalescence period

4) the incubation period

5) the decline period

1) the illness period

Among the virulence factors produced by Staphylococcus aureus are hemolysin, coagulase, hyaluronidase, and enterotoxin. Which of these factors contribute to the ability of S. aureus to invade the body?

1) hemolysin

2) enterotoxin

3) coagulase

4) hyaluronidase

5) coagulase and hemolysin

4) hyaluronidase

Symptoms are

1) laboratory tests used to diagnose a disease.

2) subjective characteristics of a disease that only the patient can feel.

3) objective manifestations of a disease that can be measured.

4) objective manifestations of a disease that can be observed by others.

5) characteristics of a disease, such as sweating.

2) subjective characteristics of a disease that only the patient can feel.

The bacterium Staphylococcus aureus is commonly found in the nasal cavity of healthy people. If inhaled into the lungs, however, it may cause pneumonia. Staphylococcus aureus is best described as

1) transient microbiota.

2) a parasite.

3) a mutualist symbiotic partner.

4) resident microbiota.

5) both resident microbiota and opportunistic pathogen.

5) both resident microbiota and opportunistic pathogen.

Chagas' disease is transmitted by a bug with mouthparts that penetrate blood vessels. Which type of exposure does this represent?

1) contact

2) parenteral route

3) skin portal

4) mucous membrane portal

5) fomite

2) parenteral route

Which of the following is NOT an example of symbiosis?

1) microbes crossing the placenta to the fetus

2) bacteria in the human colon

3) tapeworm in the human intestine

4) protozoa in termites

5) tuberculosis in the human lung

1) microbes crossing the placenta to the fetus

Sebum contains ________ which contributes to creating an inhospitable environment on the surface of the body.

1) acids

2) lysozyme

3) salts

4) bile

5) collagens

1) acids

The leukocytes called natural killer lymphocytes

1) release prostaglandins and leukotrienes in response to microbes.

2) increase in allergies and helminth infection.

3) are nonspecific leukocytes that secrete toxins onto the surface of virus-infected cells.

4) are specialists in killing bacteria.

5) respond to the coating of a pathogen by complement.

3) are nonspecific leukocytes that secrete toxins onto the surface of virus-infected cells.

TLRs are

1) phagocyte receptors that detect PAMPs.

2) the coatings of pathogens by complement.

3) present in intact skin, sebum, tears, etc.

4) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

5) molecules that damage cells, resulting in cell lysis.

1) phagocyte receptors that detect PAMPs.

Microbial molecules detected by phagocytes are called

1) PAMPs.

2) prostaglandins.

3) NODs.

4) leukotrienes.

5) TLRs.

1) PAMPs.

Which of the following statements is true of eosinophils?

1) They decline during allergic reaction.

2) They release prostaglandins and leukotrienes in response to microbes.

3) They produce the coating of a pathogen by complement.

4) They secrete toxins onto the surface of helminth parasites.

5) They are in intact skin, sebum, tears, etc.

4) They secrete toxins onto the surface of helminth parasites.

A type of lymphocyte called a(n) ________ detects cells with abnormal surface proteins and kills them.

1) mast cell

2) neutrophil

3) eosinophil

4) basophil

5) NK cell

5) NK cell

Proteins on the surface of phagocytes called ________ aid in the detection of pathogen molecules.

1) NOD proteins

2) lectins and C3 protein

3) lectins

4) TLRs

5) both TLRs and NOD proteins

4) TLRs

Opsonization is

1) the sticking of monocytes to the wall of the blood vessels at the site of infection.

2) the coating of a pathogen by complement to facilitate phagocytosis.

3) phagocyte receptors detecting PAMPs.

4) damage resulting in cell lysis.

5) nonspecific leukocyte secretion of toxins onto the surface of virally infected cells.

2) the coating of a pathogen by complement to facilitate phagocytosis.

The phenomenon known as chemotaxis is defined as options:

1) the release of prostaglandins and leukotrienes in response to microbes.

2) the squeezing of cells through the lining of capillaries.

3) the movement of a cell toward or away from a chemical stimulus.

4) the coating of a pathogen by complement.

5) an increase in allergies and helminth infection.

3) the movement of a cell toward or away from a chemical stimulus.

Which of the following acts as a chemotactic factor?

1)C5a

2) MAC

3) leukotriene

4) interferon β

5) factor P

1)C5a

Which of the following are macrophage functions?

1) phagocytosis of pathogens and production of NETs

2) release of alpha interferon

3) production of NETs

4) phagocytosis of pathogens and debris

5) phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

How does aspirin act to decrease the symptoms of inflammation?

1) it blocks the release of histamine.

2) it acts as an antiprostaglandin.

3) it is an antitoxoid for most microbial toxins.

4) it interferes with the action of interferons.

5) it prevents complement activation.

2) it acts as an antiprostaglandin.

Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead and dying tissue cells, leukocytes, and pathogens?

1) a tumor

2) an abscess

3) a boil

4) a pimple

5) a pustule

1) a tumor

Which of the following substances contributes to the edema associated with inflammation?

1) interferon

2) leukotrienes

3) histamine

4) defensin

5) both leukotrienes and histamine

5) both leukotrienes and histamine

Fever is beneficial during viral infection because the higher temperature

1) increases the effectiveness of interferons.

2) inactivates interferons.

3) prevents viral infection of fibroblasts.

4) increases vasodilation, contributing to inflammation.

5) increases sweating and consequently the barrier effect.

1) increases the effectiveness of interferons.

The alternative pathway of complement cascade activation begins with ________ binding to the surface of a microbe.

1) factor B

2) C5a

3) C5b

4) C3b

5) C1

4) C3b

What are NOD proteins?

1) cytoplasmic receptors of microbial molecules

2) activators of complement

3) cellular signals triggering inflammation

4) chemotactic factors

5) receptors of microbial molecules in phagocyte cell membranes

1) cytoplasmic receptors of microbial molecules

Alpha and beta interferons

1) are produced by infected fibroblasts and macrophages.

2) protect the cells that secrete them from being invaded by a virus.

3) produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent the attachment of pathogenic viruses.

4) help protect virus-infected cells from the effects of the pathogen.

5) produce no adverse effects in the body.

1) are produced by infected fibroblasts and macrophages.

Which of the following statements regarding phagocyte recognition of pathogens is true?

1) MACs on the surface of microbes are detected by NOD proteins.

2) Lectins on the surface of microbes are bound by chemokine receptors.

3) NOD proteins on the surface of microbes are detected by TLRs.

4) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

5) TLRs on the surface of microbes trigger the accumulation of opsonins.

4) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

Which of the following is an iron-binding protein produced by pathogens to access the body's store of iron?

1) gastroferritin

2) transferrin

3) siderophores

4) hemolysin

5) ferritin

3) siderophores

Which of the following are among the activities of neutrophils?

1) enzyme production that leads to the formation of nitric oxide

2) release of histamines

3) formation of neutrophil extracellular traps

4) formation of neutrophil extracellular traps and release of histamines

5) formation of neutrophil extracellular traps and production of nitric oxide

5) formation of neutrophil extracellular traps and production of nitric oxide

Which of the following proteins are part of the first line of defense against microbial invasion?

1) C3 and C5

2) TLRs

3) interferons

4) NOD proteins

5) dermcidins

5) dermcidins

The components of the second line of defense against microbes may be characterized as

1) detecting the unique features of specific pathogens.

2) mechanisms to strengthen the first line of defense.

3) responders to invasion.

4) passive barriers.

5) both passive barriers and detecting specific pathogen features.

3) responders to invasion.

Which of the following cells is a component of the body's first line defense?

1) NK cell

2) goblet cell

3) microglial cells

4) monocyte

5) neutrophil

2) goblet cell

Which cell becomes a macrophage when leaving the bloodstream?

1) lymphocyte

2) eosinophil

3) neutrophil

4) monocyte

5) basophil

4) monocyte

Mannose sugar occurs on the surface of some bacteria and fungi and can trigger the

1) lectin pathway of complement activation.

2) classical pathway of complement activation.

3) release of histamines by basophils.

4) release of cytotoxins by NK cells.

5) release of NETs by neutrophils.

1) lectin pathway of complement activation.

The process of phagocytosis involve all of the following EXCEPT

1) vesicle fusion.

2) elimination.

3) adhesion.

4) chemotaxis.

5) secretion of cytotoxins.

5) secretion of cytotoxins.

Which of the following are phagocytic cells descended from monocytes?

1) alveolar macrophages

2) microglial cells

3) dendritic cells

4) alveolar macrophages and dendritic cells

5) alveolar macrophages and microglial cells

5) alveolar macrophages and microglial cells

The complement cascade and its by-products contribute to

1) triggering inflammation.

2) attracting phagocytes to sites of infection.

3) triggering release of interferons.

4) triggering inflammation and release of interferons.

5) both triggering inflammation and attracting phagocytes to sites of infection

5) both triggering inflammation and attracting phagocytes to sites of infection

Which of the following statements about eosinophil function is CORRECT?

1) They secrete toxins onto virally infected cells.

2) They attach to the surface of parasitic helminths and produce toxins that kill the parasite.

3) They identify and spre normal cells.

4) They produce defensins.

5) They are involved in the removal of neoplastic cells.

2) They attach to the surface of parasitic helminths and produce toxins that kill the parasite.

Antimicrobial peptides called ________ are secreted in sweat and damage bacteria and fungi.

1) dermcidins

2) cytokines

3) antibodies

4) complement factors

5) TLRs

1) dermcidins

What antibacterial chemical is present in tear fluid?:

1) antibodies

2) defensins

3) complement

4) lysozyme

5) interferon

4) lysozyme

Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?

1)the mucus contains a variety of antimicrobial chemicals and molecules.

2)both the mucus and the outer layer of cells are shed frequently.

3)the mucus secreted by the mucous membrane physically traps microbes.

4)the mucus is a physical trap that contains a variety of antimicrobial chemicals.

5)the mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

5)the mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

Which of the following contributes to protecting the eyes from microbial invasion?

1) a mucus layer traps and removes microbes.

2) tears contain lysozyme and salt.

3) tears mechanically flush particles from the eyes.

4) tears contain lysozyme and salt and mechanically flush particles from the eyes.

5) tears and mucus combine to trap microbes and remove them.

4) tears contain lysozyme and salt and mechanically flush particles from the eyes.

Which of the following areas of the body have mucous membranes?

1) mouth

2) urinary system

3) nasal cavity

4) mouth and nasal cavity

5) mouth, nasal cavity, and urinary system

5) mouth, nasal cavity, and urinary system

The first and second lines of defense against microbial invasion are part of

1) adaptive immunity.

2) species resistance.

3) innate immunity.

4) microbial antagonism.

5) both species resistance and adaptive immunity.

3) innate immunity.

Which of the following is the result when a CTL interacts with a virally infected cell?

1) The CTL produces oxidizing chemicals.

2) The cell releases interferon-gamma (INF-γ).

3) The cell undergoes apoptosis.

4) The cell produces MHC II with epitope attached.

5) The CTL produces IL-12.

3) The cell undergoes apoptosis.

How is the development of autoimmunity normally prevented?

1) Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells.

2) T lymphocytes require a specific set of cytokine signals to become activated.

3) T lymphocytes that respond to autoantigens in the thymus undergo clonal deletion.

4) Regulatory T cells suppress autoimmune responses.

5) Clonal deletion of T cells and regulatory T cell suppression prevent autoreactive T cell activation.

1) Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells.

IgE antibodies are best described as

1) those involved in complement activation.

2) a cause of basophil and eosinophil degranulation.

3) the most common type of antibody in the blood during the initial phases of an immune response.

4) the antibodies found in body secretions.

5) the trigger for antibody-dependent cellular toxicity (ADCC).

2) a cause of basophil and eosinophil degranulation.

Which of the following best describes IgM antibodies?

1) They interact with phagocytes and NK cells.

2) They are the antibody class found in body secretions.

3) They cause basophils and eosinophils to degranulate.

4) They can cross the placenta to provide passive immunity.

5) They are the most common type of antibody in the blood during the initial stages of an immune response.

5) They are the most common type of antibody in the blood during the initial stages of an immune response.

Vaccination triggers an immune response which produces ________ immunity.

1) artificial passive

2) artificial active

3) natural passive

4) natural active

5) both active and passive

2) artificial active

Which of the following is true of chemokines?

1) They ensure production of enough leukocytes.

2) They are substances used to signal between leukocytes.

3) They are involved in B lymphocyte activation and differentiation.

4) They are chemotactic factors for leukocytes.

5) They cause basophils and eosinophils to degranulate.

4) They are chemotactic factors for leukocytes.

What is the result when a dendritic cell phagocytizes a microbe and processes it?

1) display of epitope-MHC I complexes on the surface of the cell

2) display of microbial fragments with CD8 glycoproteins

3) activation of the dendritic cell to become a plasma cell

4) display of microbial epitope-MHC II complexes on the cell surface

5) suppression of the immune response to the microbe

4) display of microbial epitope-MHC II complexes on the cell surface

Which of the following cytokines promotes the development of a cell-mediated immune response?

1) IL-12

2) alpha interferon

3) IL-4 (interleukin-4)

4) tumor necrosis factor (TNF)

5) chemokines

1) IL-12

What is the role of interleukins?

1)signaling between leukocytes

2)chemotaxis of leukocytes

3)production of virally infected cells

4)complement activation

5)ensuring production of enough leukocytes

1)signaling between leukocytes

Which of the following statements regarding the lymphatic system is FALSE?

1) Lymph fluid is similar to blood plasma.

2) Fluid flows through lymph nodes on its way to the bloodstream.

3) The lymphatic vessels have valves to control the direction of fluid flow.

4) The lymphatic system begins with highly permeable capillaries.

5) The lymphatic vessels contract to move lymphatic fluid.

5) The lymphatic vessels contract to move lymphatic fluid.

A sick child may have influenza or RSV. These virus infections have different treatment options, so the physician requests antibody titer tests. The results are as follows: anti-influenza antibodies are primarily IgM, and anti-RSV antibodies are all IgA and IgG. Which of the following is the most appropriate interpretation?

1) the child has concurrent influenza and RSV infections.

2) the child currently has influenza and has previously been exposed to RSV.

3) the child has neither influenza nor RSV.

4) the child has a current RSV infection and was previously exposed to influenza.

5) the results do not provide sufficient data to draw a conclusion.

2) the child currently has influenza and has previously been exposed to RSV.

What type of immunity is produced by the body when a person contracts a disease?

1) artificially acquired passive immunity

2) naturally acquired active immunity

3) innate immunity

4) artificially acquired active immunity

5) naturally acquired passive immunity

2) naturally acquired active immunity

The immunological synapse refers to the

1) activation of a B cell to become a plasma cell.

2) interaction between lymphocytes and foreign antigens to produce memory cells.

3) binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting cell.

4) interaction of the many cytokines produced by different immunological cells.

5) interaction between a T cell and an antigen-presenting cell to produce a specialized cell-to-cell contact area.

5) interaction between a T cell and an antigen-presenting cell to produce a specialized cell-to-cell contact area.

The perforin-granzyme pathway involves

1) the production of antibodies toward the invading pathogen.

2) presenting the foreign antigen to B cells.

3) the production of fever, which kills the pathogen.

4) binding CD95L to infected cells, which eventually leads to cell apoptosis.

5) the production of special cell-killing proteins that act on infected or abnormal cells.

5) the production of special cell-killing proteins that act on infected or abnormal cells.

The protozoan that causes malaria is an intracellular parasite of red blood cells (RBCs). An adaptive immune response to this parasite is problematic because

1) the parasite damages leukocytes along with RBCs.

2) RBCs never enter lymphoid tissue.

3) RBCs normally produce cytokines necessary for adaptive immune response, which this infection prevents.

4) red blood cells do not produce MHC and, therefore, do not display the fact that they have been infected by presenting antigen.

5) complement cannot effectively destroy RBCs.

4) red blood cells do not produce MHC and, therefore, do not display the fact that they have been infected by presenting antigen.

Which of the following statements regarding the cell-mediated immune response is TRUE?

1) Cytotoxic T lymphocytes do not require antigen presentation to become activated.

2) A single cytotoxic T lymphocyte can kill many target cells.

3) Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target.

4) Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes.

5) Cytotoxic T lymphocytes kill by producing hydrogen peroxide.

2) A single cytotoxic T lymphocyte can kill many target cells.

Enhanced immune responses to subsequent exposures to an antigen to which the body has already been exposed are known as ________ responses.

1) third-degree immune

2) primary immune

3) allergic

4) autoimmune

5) memory

5) memory

Which of the following statements concerning plasma cells is FALSE?

1) They secrete a single type of antibody molecule specific for a single epitope.

2) They are descended from activated B cells.

3) The antibodies they produce can remain in circulation for weeks.

4) They can produce large quantities of antibodies on a daily basis.

5) They live for many years and function as memory cells.

5) They live for many years and function as memory cells.

Which of the following recognizes and binds to MHC I proteins and helps stabilize the binding of epitopes to T cell receptors?

1) MHC I

2) CD26

3) CD8

4) CD4

5) CD95

3) CD8

Exogenous antigens are processed for immune recognition by ________ cells.

1) helper T

2) dendritic

3) all nucleated

4) macrophage

5) dendritic and macrophage

5) dendritic and macrophage

Class II MHC are found on

1) red blood cells.

2) cytoplasmic membranes of nucleated cells.

3) professional antigen-presenting cells.

4) the skin.

5) muscle cells.

3) professional antigen-presenting cells.

Class I MHC molecules are essential for

1) presentation of endogenous antigens.

2) detection of IL-2.

3) recognition of class II MHC.

4) recognition of chemokines.

5) presentation of exogenous antigens.

1) presentation of endogenous antigens.

Major histocompatibility antigens are

1) not really antigens, but rather antibodies produced to mask foreign antigens.

2) antigens that provoke allergic reactions.

3) autoantigens involved in epitope recognition.

4) antigens that must be processed to be recognized by the immune system.

5) antigens attached to foreign invaders.

3) autoantigens involved in epitope recognition.

The lymphocytes of adaptive immunity called ________ mature in the red bone marrow.

1) B cells

2) T cells

3) NK cells

4) macrophages

5) dendritic cells

1) B cells

Clonal deletion of developing T lymphocytes takes place in which location(s) in the body?

1) the liver

2) the bone marrow

3) the spleen

4) both the bone marrow and the spleen

5) the thymus

5) the thymus

Which of the following statements about T lymphocytes is FALSE?

1) T lymphocytes directly attack cells and produce the cell-mediated immune response.

2) T lymphocytes produce antibody molecules.

3) There are three types of T lymphocytes.

4) T lymphocytes have TCRs that recognize antigen only if it is bound to MHC.

5) T lymphocytes are called such because they mature in the thymus.

2) T lymphocytes produce antibody molecules.

Which of the following cytokines act as a signal between leukocytes?

1) interleukins

2) growth factors

3) chemokines

4) tumor necrosis factors

5) interferons

1) interleukins

Which of the following statements concerning B cell receptors (BCRs) is FALSE?

1) Scientists estimate that each person forms at least 1011 different types of B lymphocytes with distinct BCRs.

2) They are formed in response to an encounter with an antigen.

3) Each B lymphocyte is randomly generated with antibody variable regions that determine its BCR.

4) They are bound to the surface of B lymphocytes and have two antigen-binding sites.

5) They are complementary in shape to a specific antigenic determinant that they may or may not encounter.

2) They are formed in response to an encounter with an antigen.

Which of the following function in agglutination?

1) IgE antibodies

2) IgA antibodies

3) IgG antibodies

4) IgD antibodies

5) IgA and IgG antibodies

5) IgA and IgG antibodies

Secretory IgA antibodies are unique because they

1) are present in the plasma.

2) are present in lymph nodes.

3) have unique light chains.

4) are connected with J chains and short polypeptides to form dimers.

5) are Y-shaped molecules.

4) are connected with J chains and short polypeptides to form dimers.

You step on something in the yard resulting in a puncture wound that does not bleed freely. Antigens from any microbes that entered the wound will most likely end up in the

1) lymph nodes of the groin.

2) spleen.

3) appendix.

4) lymph nodes of the neck (cervical).

5) lymph nodes of the armpit (axilla).

1) lymph nodes of the groin.

Adaptive immunity is sometimes also called acquired immunity. Which of the following statements provides a basis for the alternative name?

1) Lymphocytes reactive to normal body components are removed.

2) To become activated, lymphocytes require exposure to the epitope for which they are specific.

3) Activated lymphocytes produce daughter cells that are identical in specificity and function.

4) Lymphocytes of the adaptive immune system are highly specific for a single epitope.

5) Activated lymphocytes may persist for years in the body.

2) To become activated, lymphocytes require exposure to the epitope for which they are specific.

Which of the following is a characteristic of the third line of defense that makes it significantly different from the second line?

1) The responding cells are a variety of cell types.

2) The response is specific to a single antigen.

3) The response is effective on a broad range of antigens.

4) The response to a second exposure is similar to the response to a first exposure.

5) The initial response is very rapid, beginning in minutes to a couple of hours.

2) The response is specific to a single antigen.

Rabies virus can be directly detected in brain tissue using a(n) ________ assay.

1) viral neutralization

2) direct fluorescent antibody

3) immunoblot

4) viral hemagglutination inhibition

5) immunodiffusion precipitation

2) direct fluorescent antibody

Infection with HIV is routinely verified using a(n) ________ assay.

1) viral hemagglutination inhibition

2) viral neutralization

3) immunodiffusion precipitation

4) direct fluorescent antibody

5) immunoblot

5) immunoblot

Serologic tests may be used to detect ________ for diagnosis of disease.

1) the proportion of plasma in a patient's blood

2) specific epitopes

3) the concentration of serum proteins

4) the ability of the patient's antibodies to activate the complement system

5) antigen-specific antibodies

5) antigen-specific antibodies

The complement fixation test uses red blood cells as the target for complement activation. Test serum containing antibodies is combined with a known amount of antigen in a tube, and then the RBCs and antibodies against the RBCs are added. A positive result for the complement fixation test would be

1) a cloudy solution in the tube.

2) loss of color in the tube.

3) a solution that is clear due to precipitation of RBCs.

4) a fluorescent precipitate.

5) a line of precipitate near the bottom of the tube.

1) a cloudy solution in the tube.

A hemagglutination test is useful for

1) determining effectiveness of immunization.

2) blood typing.

3) diagnosing viral infection.

4) determining antibody titer.

5) detecting presence of a pathogen in patient serum.

2) blood typing.

Which of the following statements regarding ELISAs is TRUE?

1) They can be used to detect antibody or antigen.

2) They require large amounts of serum.

3) They involve the use of membrane filters.

4) They are not quantitative.

5) The antibody label is a fluorescent molecule.

1) They can be used to detect antibody or antigen.

Viral neutralization testing is based on the fact that

1) antibodies to certain microbes can be given a fluorescent label.

2) viruses introduced into appropriate cell cultures have a cytopathic effect.

3) antibodies have different molecular weights.

4) antibodies can be produced against the toxin of a pathogen.

5) the gene for a pathogen's antigen can be isolated and introduced into a host cell by way of a plasmid.

2) viruses introduced into appropriate cell cultures have a cytopathic effect.

A person who has been exposed to rabies receives both HRIG (human rabies immunoglobulin) injected near the bite site and the rabies vaccine. What does this strategy represent?

1) active immunization

2) Viral hemagglutination inhibition

3) passive immunotherapy

4) passive immunotherapy combined with viral hemagglutination inhibition

5) active immunization combined with passive immunotherapy

5) active immunization combined with passive immunotherapy

Pathogens may be attenuated for use in vaccines by

1) genetic manipulation.

2) treatment with formaldehyde.

3) raising the pathogen for several generations in tissue culture cells.

4) genetic manipulation coupled with treatment with formaldehyde.

5) genetic manipulation and/or raising the pathogen for several generations in tissue culture cells.

5) genetic manipulation and/or raising the pathogen for several generations in tissue culture cells.

Systemic lupus erythematosus (SLE or lupus) is distinct from other autoimmune disorders because

1) it involves an antibody response.

2) there is a genetic predisposition.

3) it is also a hypersensitivity disorder.

4) it may be triggered by an infection.

5) multiple organs and tissues are affected.

5) multiple organs and tissues are affected.

The syndrome known as AIDS is characterized

1) by the presence of anti-HIV antibodies.

2) as an opportunistic disease resulting from herpesvirus reactivation.

3) by CTL attack on CD4 T cells.

4) by one or more opportunistic diseases and the presence of HIV.

5) by the presence of HIV.

4) by one or more opportunistic diseases and the presence of HIV.

Which of the following statements concerning allografts is TRUE?

1) They induce strong type IV hypersensitivity reactions and must be treated with immunosuppressive drugs.

2) They are the best type of transplants because they are not associated with rejection.

3) They are impossible to perform because the antigens between donor and recipient are so different.

4) They always require complete destruction of the recipient's bone marrow cells.

5) They are the rarest type of transplants.

1) They induce strong type IV hypersensitivity reactions and must be treated with immunosuppressive drugs.

Hypotheses explaining the development of autoimmune disease include

1) genetic factors.

2) overuse of vaccines.

3) molecular mimicry and vaccines.

4) molecular mimicry and genetic factors.

5) molecular mimicry.

4) molecular mimicry and genetic factors.

A young woman comes into the clinic complaining of itchy, red skin and swelling on her arms and legs. She had not been in any parks or wooded areas recently, but she had been shopping. A blood sample reveals elevated levels of granulocytes. What treatment is the physician likely to prescribe at this point?

1) cyclophosphamide

2) methylprednisolone

3) azathioprine

4) antihistamines

5) corticosteroids

4) antihistamines