Ch. 21: The Immune System

A graft from a monkey to a human is an example of an allograft.False
The mechanism of the “lethal hit” of cytoxic T cells and NK cells involves a protein called perforin.True
Cellular ingestion and destruction of particulate matter is called phagocytosis.True
The respiratory burst produced by some macrophages releases free radicals.True
The directional movement of cells in response to chemicals is called chemotaxis.True
Substances capable of triggering the adaptive immune system and provoking an immune response are called antigens.True
Soluble proteins secreted by plasma cells are called antibodies.True
A given pathogen will provoke either a cell-mediated response or an antibody-mediated response but not both.False
Fever is seldom beneficial because it speeds up the cellular metabolic rate and will not allow antigen-antibody reactions to occur.False
Monoclonal antibodies can be specific for several antigenic determinants.False
Both T cells and B cells must accomplish double recognition: They must simultaneously recognize self and nonself to be activated.False
Some immunocompetent cells will never be called to service in our lifetime.True
Anaphylactic shock can result from an immediate hypersensitivity where the allergen enters the blood.True
Adaptive immunity is provided only by lymphocytes that secrete antibodies.False
A transfusion reaction is a subacute hypersensitivity to foreign red blood cells.True
Somatic recombination by B cells allows each B cell to form its own unique antibody genes.True
Antigens can be complete or incomplete.True
It is our genes, not antigens, that determine what specific foreign substances our immune system will be able to recognize and resist.True
Which of the following is characteristic of antibodies?
A) carbohydrate structure
B) composed of heavy and light polypeptide chains
C) three binding sites per antibody monomer
D) incapable of being transferred from one person to another
B) composed of heavy and light polypeptide chains
Which of the following is associated with passive immunity?
A) exposure to an antigen
B) infusion of weakened viruses
C) passage of IgG antibodies from a pregnant mother to her fetus
D) booster shot of vaccine
C) passage of IgG anitbodies form a pregnant mother to her fetus
Which of the following is not a type of T cell?
A) cytotoxic
B) antigenic
C) helper
D) regulatory
B) antigenic
B lymphocytes develop immunocompetence in the ________.
A) thymus
B) spleen
C) bone marrow
D) lymph nodes
C) bone marrow
Which of the following is not a function of the inflammatory response?
A) prevents the spread of the injurious agent to nearby tissue
B) replaces injured tissues with connective tissue
C) disposes of cellular debris and pathogens
D) sets the stage for repair processes
B) replaces injured tissues with connective tissue
The redness and heat of an inflamed area are due to a local hyperemia caused by ________.
A) vasodilation
B) vasoconstriction
C) phagocyte mobilization
D) production of complement and interferon
A) vasodilation
The antibody molecule is held together by ________ bonds.
A) disulfide
B) hydrogen
C) amino acid
D) sodium
A) disulfide
In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
A) antigen
B) interferon
C) antibody
D) complement
A) anitgen
Which of the following statements regarding NK cells is a false or incorrect statement?
A) NK cells are a type of neutrophil.
B) NK cells are present in the blood, spleen, lymph nodes, and red bone marrow.
C) NK cells attack cells that display abnormal MHC antigens.
D) NK cells attack cancer cells and virus-infected body cells.
A) NK cells are a type of neutrophil
The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is called ________.
A) diapedesis
B) chemotaxis
C) margination
D) phagocytosis
B) chemotaxis
Small molecules that bind with self-proteins to produce antigenic substances are called ________.
A) haptens
B) antibodies
C) ions
D) reagins
A) haptens
Which of the following is the correct sequence of events in phagocytosis? A) adherence, digestion, killing, ingestion, chemotaxis
B) chemotaxis, ingestion, digestion, adherence, killing
C) chemotaxis, adherence, ingestion, digestion, killing
D) ingestion, adherence, chemotaxis, digestion, killing
C) chemotaxis, adherence, ingestion, digestion, killing
The only T cells that can directly attack and kill other cells are the ________.
A) regulatory cells
B) helper cells
C) cytotoxic cells
D) plasma cells
C) cytotoxic cells
Which of the following does not respond to cell-mediated immunity? A) intracellular pathogens that reside within host cells
B) some cancer cells
C) foreign tissue transplants
D) pathogens in the CNS
D) pathogens in the CNS
________ predominate at the sites of chronic infections.
A) Basophils
B) Eosinophils
C) Macrophages
D) B cells
C) Macrophages
Interferons ________.
A) are virus-specific, so that an interferon produced against one virus could not protect cells against another virus
B) act by increasing the rate of cell division
C) interfere with viral replication within cells
D) are routinely used in nasal sprays for the common cold
C) interfere with viral replication within cells
________ determine(s) what specific foreign substances our adaptive immune system will be able to recognize and resist.
A) The type of antigen
B) Memory cell production
C) Enzymes present at the time of the invasion
D) Our genes
D) Our genes
Regulatory T cells ________.
A) release cytokines that increase the activity of cytotoxic T cells and activated B cells
B) decrease their activity as antigenic stimulus decreases
C) may function in preventing autoimmune reactions
D) are the most thoroughly understood T cells
C) may function in preventing autoimmune reactions
Select the correct definition about tissue grafts.
A) Isografts are between identical twins.
B) Allografts are between different species.
C) Xenografts are between individuals of the same species.
D) Autografts are between two genetically identical individuals.
A) Isografts are between identical twins
Which of the statements below does not describe antigens?
A) Antigens exhibit immunogenicity and reactivity.
B) Antigens only come from microbes.
C) The parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants.
D) Antigens can include proteins, nucleic acids, lipoproteins, glycoproteins, and certain large polysaccharides.
B) Antigens only come from microbes
________ are released by activated T cells and macrophages to mobilize immune cells and attract other leukocytes into the area.
A) Cytokines
B) Perforins
C) Interleukin 1 proteins
D) Interleukin 2 proteins
A) Cytokines
Which of the following is a part of the second line of defense against microorganisms?
A) keratin
B) cilia
C) gastric juice
D) phagocytes
D) Phagocytes
Which of the following is characteristic of complete antigens? A) small molecules
B) reactivity with an antibody
C) contain many repeating chemical units
D) inhibit production of antibodies
B) reactivity with an antibody
B cells respond to the initial antigen challenge by ________.
A) reducing its size
B) immediately producing antigen-specific antibodies
C) forming of a large number of cells that are unlike the original B cell
D) producing progeny cells that include plasma cells and memory cells
D) Producing progeny cells that include plasma cells and memory cells
Graft rejection may be caused by ________.
A) using an xenograft
B) use of immunosuppressive drugs
C) treatment with antilymphocyte serum
D) total body irradiation
A) using an xenograft
Cancer cells and virus-infected body cells can be killed before activation of adaptive immunity by ________.
A) natural killer cells
B) T lymphocytes
C) B lymphocytes
D) pinocytosis
A) natural killer cells
Complement proteins and antibodies coat a microorganism and provide binding sites, enabling macrophages and neutrophils to phagocytize the organism. This phenomenon is termed ________.
A) diapedesis
B) agglutination
C) opsonization
D) chemotaxis
C) opsonization
Which of the following is not characteristic of the adaptive immune system?
A) It is antigen-specific.
B) It is systemic.
C) It has memory.
D) It is specific for a given organ.
D) It is specific for a given organ
Monoclonal antibodies are used for the diagnosis of all of the following except ________.
A) juvenile diabetes
B) hepatitis
C) rabies
D) pregnancy
A) juvenile diabetes
Which of the following would be classified as a delayed hypersensitivity reaction?
A) immune complex hypersensitivity
B) anaphylaxis
C) cytotoxic hypersensitivity
D) allergic contact dermatitis
D) allergic contact dematitis
Innate immune system defenses include ________.
A) B cells
B) T cells
C) plasma cells
D) phagocytosis
D) phagocytosis
Which of the following statements is incorrect or false?
A) Haptens lack immunogenicity unless attached to protein carriers.
B) Class 1 MHC molecules are built into the plasma membranes of all body cells.
C) Class II MHC molecules appear only on the surface of antigen-presenting cells, thymic cells, and T cells that have been activted by exposure to antigens.
D) MHC proteins are the cell’s identity markers.
C) Class II MHC molecules appear only on the surface of antigen-presenting cells, thymic cells, and T cells that have been activted by exposure to antigens.
Phagocyte mobilization involves ________.
A) diapedesis, during which cells line up against the capillary wall
B) margination, which is the process of white cell movement through the walls of capillaries into injured tissues
C) mainly neutrophil and macrophage migration into inflamed areas
D) monocytes as the most active phagocyte
C) mainly neutrophil and macrophage migration into inflamed areas
Fever ________.
A) is a higher-than-normal body temperature that is always dangerous
B) decreases the metabolic rate of the body to conserve energy
C) production is regulated by chemicals that reset the body’s thermostat to a higher setting
D) causes the liver to release large amounts of iron, which seems to inhibit bacterial replication
C) production is regulated by chemicals that reset the body’s thermostat to a higher setting
Immunocompetence ________.
A) occurs in one specific organ of the adaptive immune system
B) is the ability of individual cells to recognize a specific antigen by binding to it
C) prevents intercellular communication so that only specific cell types respond to the invader
D) requires exposure to an antigen
B) is the ability of individual cells to recognize a specific antigen by binding to it
Select the correct statement about the prevention of immune attack on “self.”
A) The development of tolerance is specific to B cells only.
B) Neutrophils capable of binding to self-antigens are chemically inactivated.
C) Tolerance to self is due to the action of foreign antigens that inactivate the immune response to one’s own tissues.
D) Tolerance is developed during fetal life.
D) Tolerance is developed during fetal life.
Select the correct statement about active and passive immunity.
A) Immunological memory is established by passive immunization.
B) A vaccination is an example of the introduction of passive immunity into the body.
C) The antibodies utilized in active immunity are acquired from another organism.
D) Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.
D) Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.
Cytotoxic T cells ________.
A) are the only T cells that can directly attack and kill other cells
B) require the double recognition signal of I MHC plus II MHC on the target cell in order to function
C) function mainly to stimulate the proliferation of other T cell populations
D) self-destruct once the antigen has been neutralized
A) are the only T cells that can directly attack and kill other cells
Helper T cells ________.
A) bind tightly to target cells and release a lymphotoxin called perforin B) often function to decrease the immune response
C) release B7 proteins
D) function in the adaptive immune system activation
D) function in the adaptive immune system activation
Select the correct statement about immunodeficiency.
A) Severe combined immunodeficiency (SCID) disease is an acquired condition.
B) The causative agent is acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins.
C) Hodgkin’s disease is a hereditary immunodeficiency found in children.
D) The most common form of immunodeficiency is graft-versus-host (GVH) disease.
B) The causative agent is acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins.
Which of the following is true of immediate hypersensitivities?
A) They are also called type IV hypersensitivities.
B) They are are adaptive immune responses to disease organisms.
C) They include allergic contact dermatitis.
D) They involve IgE antibodies and the release of histamine from mast cells and basophils.
D) They involve IgE anitbodies and the release of histamine from mast cells and basophils
Delayed hypersensitivities ________.
A) are mediated by B cells
B) include allergic contact dermatitis
C) include anaphylactic shock, a systemic vasodilation that results in inadequate blood delivery to all tissues
D) do not involve T cells
B) include allergic contact dermatitis
Natural killer (NK) cells ________.
A) are also called cytotoxic T cells
B) are a type of phagocyte
C) are cells of the adaptive immune system
D) can kill cancer cells before the immune system is activated
D) can kill cancer cells before the immune system is activated
Select the correct statement about antigens.
A) “Self-antigens” is another name for incomplete antigens.
B) The largest type of antigen is called a hapten.
C) Only small antigens exhibit reactivity.
D) One antigen may have many different antigenic determinants and may therefore cause the
formation of more than one antibody.
D) One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.
Clonal selection of B cells ________.
A) occurs during fetal development
B) results in the formation of plasma cells
C) cannot occur in the presence of antigens
D) only occurs in the secondary immune response
B) results in the formation of plasma cells
The primary immune response ________.
A) occurs more rapidly and is stronger than the secondary response
B) occurs when memory cells are stimulated
C) is another name for immunological memory
D) has a lag period while B cells proliferate and differentiate into plasma cells
D) has a lag period while B cells proliferate and differentiate into plasma cells
Select the correct statement about the function of antibodies.
A) Antibodies may directly destroy “invaders.”
B) Neutralization is the process by which antibodies cause invading cells to clump together.
C) Complement fixation is the main mechanism by which antibodies provide protection.
D) The most potent agglutinating agent is IgG.
C) Complement fixation is the main mechanism by which antibodies provide protection.
Which of the following cells is the most critical cell in immunity?
A) B cell
B) helper T cell
C) cytotoxic T cell
D) APC
B) helper T cell
Which of the following is not an autoimmune disease?
A) multiple sclerosis
B) type II diabetes
C) systemic lupus erythematosus
D) glomerulonephritis
B) Type II diabetes
Which of the following is not a mechanism for the development of autoimmune disorders?
A) exposure of previously “hidden” self-antigens to the adaptive immune system
B) a second exposure to an allergen
C) mutation followed by the appearance of membrane proteins not previously present
D) cross-reaction of antibodies formed against foreign antigens with self-antigens
B) a second exposure to an allergen
Select the correct statement about complement.
A) An adaptive immune mechanism is often involved in directing complement to its target.
B) Complement can be activated through three pathways: classical, secondary, and alternate.
C) The membrane attack complex consists of complement proteins C3a through C5.
D) Complement proteins C1 through C9 act exclusively in the classical pathway.
A) An adaptive immune mechanism is often involved in directing complement to its target.
Which of the following is true about the number of binding sites per functional antibody unit?
A) IgD contains 4 binding sites.
B) IgA contains 6 binding sites.
C) IgG contains 6 binding sites.
D) IgM contains 10 binding sites.
D) IgM contains 10 binding sites
Antibody functions include all of the following except ________.
A) binding and inactivating chemical toxins released by bacteria or other microorganisms
B) cross-linking cell-bound antigens on red blood cells when blood types are properly matched
C) linking soluble antigens together so that they fall out of solution
D) targeting foreign cells so that complement proteins can cause cellular lysis
B) cross-linking cell-bound antigens on red blood cells when blood types are properly matched
Which statement is true about T cells?
A) They usually directly recognize antigens, which then activates a subpopulation of killer cells.
B) Their proliferation is enhanced by interleukins 1 and 2.
C) Once activated, they cannot secrete cytokines.
D) They will develop into cytotoxic T cells if antigen is complexed with class II MHC proteins.
B) Their proliferation is enhanced by interleukins 1 and 2.
Toll-like receptors (TLRs) trigger the release of ________ to attract white blood cells to the scene.
A) cytokines
B) histamine
C) prostaglandins
D) complement
A) cytokines
Which of the following is not a method by which antibodies work? A) neutralizing antigen
B) activating cytokines
C) enhancing phagocytosis
D) agglutinating and precipitating antigen
B) activating cytokines
What is the role of interferon in defense against disease?
A) protects cells that have not yet been infected by viruses
B) protects cells that have not yet been infected by bacteria
C) activates the complement mechanism
D) activates the inflammatory process
A) protects cells that have not yet been infected by viruses
Which of the following statements is a false or incorrect statement?
A) The lymphoid organs where lymphocytes become immunocompetent are called primary lymph organs. All other lymphoid organs are referred to as secondary lymphoid organs.
B) It is our genes, not antigens, that determine what specific foreign substances our immune system will be able to recognize and resist.
C) After becoming immunocompetent, the naive T cells and B cells are exported to the bone marrow where the encounters with antigens occur.
D) T cells and B cells become fully immunocompetent when they bind with recognized antigens.
C) After becoming immunocompetent, the naive T cells and B cells are exported to the bone marrow where the encounters with antigens occur.