Deck 42: Immunology: Animal Defense Systems

Question 1

T cell receptors

A) are the primary receptors for the humoral immune system.
B) are carbohydrates.
C) cannot function unless the animal has previously encountered the antigen.
D) are produced by plasma cells.
E) are important in combating viral infections.

Answer 1

E

Question 2

According to the clonal selection theory,

A) an antibody changes its shape to match the antigen it meets.
B) an individual animal contains only one type of B cell.
C) an individual animal contains many types of B cells, each producing one kind of antibody.
D) each B cell produces many types of antibodies.
E) many clones of antiself lymphocytes appear in the bloodstream.

Answer 2

C

Question 3

For every white blood cell in a given volume of human blood, there are about _______ red blood cells.

A) 2
B) 10
C) 50
D) 100
E) 1,000

Answer 3

E

Question 4

Which of the following is important in the immune deficiency caused by HIV?

A) Pneumonia infection by bacteria
B) Activated T_H cell infection by HIV
C) Circulating free HIV in blood plasma
D) Antibodies made against HIV-infected cells
E) Increase in T cells

Question 5

Which statement about an antigenic determinant is not true?

A) It is a specific chemical grouping.
B) It may be part of many different molecules.
C) It is the part of an antigen to which an antibody binds.
D) It may be part of a cell.
E) A single protein has only one on its surface.

Question 6

Which of the following is not a lymphoid tissue?

A) Spleen
B) Thymus
C) Bone marrow
D) Lymph nodes
E) All of the above are lymphoid tissues.

Question 7

It has been discovered only recently that the plague of Athens (during the Peloponnesian War) was likely caused by

A) smallpox.
B) the malicious spread of cowpox.
C) gangrene.
D) typhoid.
E) HIV.

Question 8

Immunological tolerance

A) depends on exposure to an antigen.
B) develops late in life and is usually life-threatening.
C) disappears at birth.
D) results from the activities of the complement system.
E) results from DNA splicing.

Question 9

The major histocompatibility complex

A) codes for specific proteins found on the surfaces of cells.
B) plays no role in T cell immunity.
C) plays no role in antibody responses.
D) plays no role in skin graft rejection.
E) is encoded by a single locus with multiple alleles.

Question 10

Which of the following is generally restricted to a closed circulatory system?

A) Platelets
B) White blood cells
C) Red blood cells
D) All of the above
E) None of the above

Question 11

The extraordinary diversity of antibodies results in part from

A) the action of monoclonal antibodies.
B) the splicing of protein molecules.
C) the action of cytotoxic T cells.
D) the rearrangement of genes.
E) their remarkable nonspecificity.

Question 12

Antibodies are made by

A) T cells.
B) Mast cells.
C) macrophages.
D) B cells.
E) All of the above

Question 13

Which of the following statements about specific and nonspecific defenses is false?

A) Defense systems involve recognition of self from nonself.
B) Nonspecific defenses typically act more rapidly than specific defenses.
C) Specific defense mechanisms are typically the body's first line of defense.
D) The skin is an example of a nonspecific defense.
E) All of the above are true; none is false.

Question 14

Which of the following play(s) no role in the B cell response?

A) T-helper cells
B) Growth factors
C) Macrophages
D) Reverse transcriptase
E) Products of class II MHC genes

Question 15

B cells mature in

A) the thymus.
B) lymph nodes.
C) bone marrow.
D) the spleen.
E) circulating blood.

Question 16

Which of the following statements about lymph is false?

A) It is filtered in the lymph nodes.
B) White blood cells inspect it in lymph nodes for pathogens and other nonself elements.
C) It is derived in part from blood.
D) It contains soluble proteins.
E) All of the above are true; none is false.

Question 17

Phagocytes kill harmful bacteria by

A) endocytosis.
B) producing antibodies.
C) complement proteins.
D) T cell stimulation.
E) inflammation.

Question 18

Which statement about immunoglobulins is true?

A) They help antibodies do their job.
B) They recognize and bind antigenic determinants.
C) They encode some of the most important genes in an animal.
D) They are the chief participants in nonspecific defense mechanisms.
E) They are a specialized class of white blood cells.

Question 19

After surviving an infection during the plague of Athens (in the Peloponnesian War), Thucydides noted that he no longer feared the disease, "for the same man was never attacked twice." Unknowingly, he was referring to

A) the fact that minute amounts of pathogen remain in the body indefinitely, preventing recolonization.
B) the role of interferons in preventing replication of microbes.
C) the earlier Roman idiom that "lightning never strikes twice," which credited Zeus with protecting the unlucky.
D) the presence of "memory cells" that are protective in case of later reexposure to the disease.
E) the tendency of microbes to deplete the resources they need from a given host, thus making recolonization unlikely.

Question 20

Which of the following statements about red and white blood cells is true?

A) Mature white blood cells have nuclei and mature red blood cells do not.
B) Mature red blood cells have nuclei and mature white blood cells do not.
C) The number of white blood cells often rises sharply upon infection.
D) Both a and c
E) Both b and c

Question 21

T cells mature in

A) the thymus.
B) lymph nodes.
C) bone marrow.
D) the spleen.
E) the thoracic duct.

Question 22

Epitopes are

A) molecules produced by mast cells.
B) produced by clonal selection.
C) specific sites on antigens that are recognized by the immune system.
D) responsible for immunological tolerance.
E) antibodies that were first discovered by Jenner.

Question 23

Which of the following does not arise from a myeloid progenitor cell?

A) Macrophage
B) T lymphocyte
C) Basophil
D) Mast cell
E) Red blood cell

Question 24

Defensins, which are toxic to a wide range of pathogens, are produced by

A) lymph nodes.
B) mucous membranes.
C) bone marrow.
D) mast cells.
E) None of the above

Question 25

Binding of a molecule from a pathogen to a receptor initiates a signal transduction pathway. Which is the correct order of events in this pathway?

A) Phosphorylation of NF- $\kappa$ B, binding of NF- $\kappa$ B to the promoter, activation of toll receptor, transcription of defense genes
B) Binding of NF- $\kappa$ B to the promoter, phosphorylation of NF- $\kappa$ B, activation of toll receptor, transcription of defense genes
C) Activation of toll receptor, phosphorylation of NF- $\kappa$ B, binding of NF- $\kappa$ B to the promoter, transcription of defense genes
D) Activation of toll receptor, binding of NF- $\kappa$ B to the promoter, phosphorylation of NF- $\kappa$ B, transcription of defense genes
E) Binding of NF- $\kappa$ B to the promoter, activation of toll receptor, transcription of defense genes, phosphorylation of NF- $\kappa$ B

Question 26

The _______ acid in gastric juice is lethal to many pathogens.

A) sulfuric
B) carbolic
C) hydrochloric
D) formic
E) protease

Question 27

Interferons are produced in response to a _______ infection.

A) viral
B) Gram-negative bacterial
C) Gram-positive bacterial
D) yeast
E) spirochete

Question 28

Which of the following is a type of defense provided by complement proteins?

A) Lysing of invading cells
B) Activation of the inflammation response
C) Assistance to phagocytes in recognizing microbes
D) All of the above
E) None of the above

Question 29

Which of the following does not occur during inflammation and wound healing?

A) Histamines cause capillaries to constrict.
B) Phagocytes engulf bacteria and other dead cells.
C) Wound healing begins when signaling molecules stimulate endothelial cell division.
D) Some cytokines elevate body temperature.
E) All of the above occur.

Question 30

Which of the following is not a key trait of the specific immunity response?

A) Ability to respond specifically to a wide diversity of foreign molecules and organisms
B) Rapid response
C) Generally long-lasting immunological memory
D) The ability to recognize "self" from "nonself"
E) All of the above are key traits.

Question 31

The bacteria and fungi that typically live and reproduce on the skin without causing disease are called

A) microcytes.
B) ectocytes.
C) pathogens.
D) normal flora.
E) normal fauna.

Question 32

Which of the following is not a nonspecific defense?

A) The skin
B) The normal fauna
C) Lysozyme
D) Defensins
E) All of the above can be used as nonspecific defenses.

Question 33

Which of the following cells release histamines upon damage?

A) Mast cells
B) Basophils
C) Macrophages
D) Monocytes
E) Both a and b

Question 34

MHC I proteins

A) are found primarily on immune system cells.
B) protect a developing fetus from its mother's immune system.
C) are found on the surface of most mammalian cells.
D) are important self-identifying labels.
E) Both c and d

Question 35

Which of the following is not a leukocyte?

A) Platelet
B) Neutrophil
C) Dendritic cell
D) Macrophage
E) Mast cell

Question 36

Which of the following statements about the complement system is false?

A) It consists of 20 different proteins.
B) It is involved in a cascade of reactions.
C) It lyses invading cells.
D) It consists of highly folded membranes that capture pathogens.
E) It interacts with phagocytes.

Question 37

Which of the following is most likely responsible for fever during inflammation?

A) Interferons
B) Complement proteins
C) Cytokines
D) Class I MHC proteins
E) Class II MHC proteins

Question 38

Interactions between macrophages and lymphocytes are coordinated by

A) antibodies.
B) T cell receptors.
C) mast cells.
D) platelets.
E) MHC proteins.

Question 39

Which of the following statements about natural killer cells is false?

A) They are a class of lymphocytes.
B) They can distinguish between normal cells and cells that have been infected by viruses.
C) They release cytokines.
D) They initiate lysis of targeted cells.
E) All of the above are true; none is false.

Question 40

Which of the following statements about the toll cell-signaling pathway is false?

A) It was originally discovered in fruit flies, but it has human counterparts.
B) It involves phosphorylation of a transcription factor.
C) It is stimulated by molecules made only by microbes.
D) It is part of the specific immunity response.
E) All of the above are true; none is false.

Question 41

The diversity among antibodies occurs mainly through

A) posttranslational modifications.
B) protein-folding differences.
C) different patterns of methylation.
D) DNA changes.
E) None of the above

Question 42

The primary immune response is _______ powerful and _______ lasting than the secondary immune response.

A) more; longer
B) more; shorter
C) more; just as long-
D) less; shorter
E) less; longer

Question 43

When a T cell is activated by an antigen, it will most likely

A) secrete antibodies.
B) proliferate.
C) die.
D) become a hybridoma.
E) become a plasma cell.

Question 44

Hybridomas are used to produce _______ antibodies.

A) IgE
B) IgG
C) IgA
D) monoclonal
E) polyclonal

Question 45

A body's tolerance to its own molecules involves

A) the removal of immature B or T cells that show the potential to mount a response against self antigens.
B) the suppression of immune response to self antigens after maturation.
C) the presence of CD28 on most cells.
D) Both a and b
E) Both b and c

Question 46

Which of the following antibody classes is most likely to trigger a large release of histamines?

A) IgE
B) IgG
C) IgM
D) IgL
E) Monoclonal

Question 47

The removal of immature B and T cells is called clonal

A) anergy.
B) deletion.
C) selection.
D) attenuation.
E) inactivation.

Question 48

Which of the following statements is true?

A) The T cell receptor is an immunoglobulin.
B) The receptors on T lymphocytes are smaller than those on B lymphocytes.
C) T cell receptors bind to intact antigens.
D) Both a and b
E) Both b and c

Question 49

Antigens can bind to an antibody at _______ site(s); binding occurs at the _______ regions of the antibody.

A) one; constant
B) one; variable
C) one; specific
D) two; variable
E) two; constant

Question 50

The _______ region of an antibody determines its class; the _______ region determines its specificity.

A) constant; specific
B) constant; variable
C) specific; constant
D) specific; variable
E) variable; constant

Question 51

Which of the following statements is true?

A) Plasma cells secrete cytokines.
B) Effector T cells secrete antibodies.
C) Memory B cells can persist in the body for several decades.
D) All of the above
E) None of the above

Question 52

Which of the following statements is false?

A) MHC proteins are plasma membrane glycoproteins.
B) The major role of MHC proteins is to present antigens to T cell receptors.
C) Class I MHC proteins are found on the surface of every nucleated cell.
D) Class II MHC molecules are found on the surfaces of T cells.
E) All of the above are true; none is false.

Question 53

Which of the following must take place for a B cell to become an antibody-secreting plasma cell?

A) Clonal anergy
B) Binding to the antigen by a helper T cell that has the same specificity as the B cell
C) The production of IgE
D) The production of IgG
E) Activation of Class I MHC proteins

Question 54

The simplest immunoglobulins have _______ polypeptide chain(s).

A) one
B) two
C) three
D) four
E) None of the above

Question 55

Lymphocytes specific for certain antigens proliferate by a process known as

A) effector selection.
B) clonal anergy.
C) class switching.
D) clonal selection.
E) monoclonal formation.

Question 56

In the human body, the most abundant antibody class is

A) IgE.
B) IgM.
C) IgG.
D) cytokine.
E) monoclonal.

Question 57

For which of the following can monoclonal antibodies not be used?

A) Immunoassays
B) Immunotherapy
C) Treating rattlesnake bites
D) HAART treatment
E) Treating the early symptoms of rabies

Question 58

When an individual is first exposed to the smallpox virus, several days pass before significant numbers of specific antibody molecules and T cells are produced. However, a second exposure to the virus causes a large and rapid production of antibodies and T cells. This response is an example of

A) antigenic determinants.
B) phytoalexins.
C) phagocytosis.
D) interferon production.
E) immunological memory.

Question 59

Which of the following statements about the humoral immune response is true?

A) It is directed against antigens that have become established within a cell.
B) It is carried out by T cells.
C) It involves soluble antibodies.
D) All of the above
E) None of the above

Question 60

Each B cell can produce _______ kind(s) of antibodies.

A) 1
B) 2 to 4
C) an average of 6
D) more than 20
E) None of the above; B cells do not produce antibodies.

Question 61

Class switching occurs as a result of

A) imprecise recombination between the immunoglobin genes.
B) clonal anergy.
C) clonal deletion.
D) genetic deletions in the immunoglobin genes.
E) changes in the variable region.

Question 62

The cells targeted by HIV are

A) neurons.
B) platelets.
C) erythrocytes.
D) mast cells.
E) T-helper cells.

Question 63

Which of the following statements is false?

A) MHC proteins often act as nonself antigens in transplants between one individual and another.
B) MHC proteins play an important role in self-tolerance.
C) Developing T cells that fail to recognize the body's own MHC proteins undergo apoptosis in a normally functioning body.
D) In transplants of material from one individual to a genetically identical individual, the material is recognized as self and is not rejected.
E) All of the above are true; none is false.

Question 64

Cells that initially become infected by HIV are

A) macrophages.
B) T_H cells.
C) dendritic cells.
D) All of the above
E) None of the above

Question 65

Which of the following play a role in the cellular immune response that is analogous to the role played by Class II MHC proteins in the humoral immune response?

A) Cytotoxic T cells
B) Helper T cells
C) CD28
D) Memory cells
E) None of the above

Question 66

The desensitization treatment for allergies involves injections of small amounts of the allergen: enough to trigger the production of _______, but not enough to trigger the production of _______.

A) IgE; IgG
B) histamines; IgM
C) histamines; IgG
D) IgG; IgE
E) IgG; IgM

Question 67

One V gene, one D gene, and one J gene encode for the _______ region of the _______ chain of a specific antibody.

A) constant; light
B) constant; heavy
C) specific; light
D) specific; heavy
E) variable; heavy

Question 68

Which of the following is not an autoimmune disease?

A) Systemic lupus erythematosis
B) Rheumatoid arthritis
C) Type I diabetes
D) AIDS
E) All of the above are autoimmune diseases.

Question 69

T cells are stimulated by the binding of antigen-MHC complex to its receptors. To be activated, T cells must also receive a second signal and bind with _______ present on certain antigen-presenting cells.

A) cytokines
B) another MHC protein
C) B7
D) CTLA4
E) defensin

Question 70

The retrovirus HIV specifically destroys helper T cells and thus disrupts the _______ response.

A) humoral immune
B) cellular immune
C) inflammatory
D) Both a and b
E) Both a and c

Question 71

Which of the following statements about AIDS is false?

A) The chances of getting the disease are increased if an individual already has a sexually transmitted disease.
B) AIDS stands for "autoimmune deficiency syndrome."
C) Most people who die from AIDS did not die because of HIV infection directly, but from other infections that would normally be eliminated by T cells.
D) HIV can be transmitted through the blood of an infected mother to her child.
E) All of the above are true; none is false.

Question 72

Rheumatoid arthritis usually arises

A) from the overproduction of IgE from mast cells.
B) due to difficulty in shutting down the T cell response.
C) from the production of antibodies to many cellular components, including DNA and nuclear proteins.
D) when B cells lose their ability to become plasma cells.
E) None of the above

Question 73

Which of the following statements is true?

A) There is little polymorphism at MHC loci in humans.
B) T cell receptors recognize antigenic fragments only when they are bound to an MHC molecule.
C) Helper T cells have a surface protein that binds to MHC Class II molecules.
D) Both a and b
E) Both b and c

Question 74

A plasma cell produces IgM molecules that recognize an antigenic determinant on an influenza virus. After several days, the cell begins to produce IgG molecules that recognize the same antigenic determinant. This process is called

A) activation.
B) RNA splicing.
C) gene mutation.
D) class switching.
E) autoimmunity.

Question 75

Terminal transferase

A) plays a role in class switching.
B) often adds nucleotides to the ends of immunoglobin gene DNAs.
C) can be used to suppress the immune system during organ transplants.
D) is a component of the HAART treatment for AIDS.
E) None of the above

Question 76

Which of the following could occur in delayed hypersensitivity?

A) Sneezing from ragweed exposure
B) Production of IgE by mast cells
C) Rash after exposure to poison oak
D) All of the above
E) None of the above

Question 77

Which of the following statements is false?

A) Mammals have a very large number of antibody genes.
B) Different B cells develop slightly different genomes.
C) The random pairing of heavy and light chains helps produce antibody diversity.
D) Each mature B cell can produce one, and only one, specific type of immunoglobin.
E) All of the above are true; none is false.

Question 78

The mechanisms of joining and random deletion account for only a part of antibody diversity. Vast numbers of unique immunoglobulins are also produced by

A) mutations.
B) translocations.
C) cell fusion.
D) cell surface proteins.
E) All of the above

Question 79

HIV can be transmitted from person to person in

A) blood.
B) semen.
C) vaginal fluid.
D) breast milk.
E) All of the above

Question 80

Helper T cells release cytokines after the cell has bound to an antigen-presenting macrophage. Then the T cell starts making a clone of like cells with the same specificity. This occurs in the _______ phase of the _______ immune response.

A) activation; cellular
B) activation; humoral
C) effector; humoral
D) effector; cellular
E) responding; cellular