Deck 15: The Adaptive Immune Response

Question 1

Cytotoxic T cells primarily are responsible for

A) humoral immunity.
B) cell-mediated immunity.
C) anamnestic immunity.
D) producing haptens.
E) producing antibodies.

Answer 1

B

Question 2

Which of the following is not typical of an antigen?

A) Protein
B) Foreign
C) Low molecular weight
D) Polysaccharide
E) Low molecular weight AND protein

Answer 2

C

Question 3

Which of the following is/are secondary lymphoid organ(s)?

A) Thymus AND spleen
B) Spleen AND lymph nodes
C) Lymph nodes AND bone marrow
D) Spleen AND bone marrow
E) Thymus AND bone marrow

Answer 3

B

Question 4

The humoral immune response is delivered by

A) antibodies.
B) T cells.
C) lymphokines.
D) antigens.
E) antibodies AND lymphokines.

Question 5

There are ________ class(es) of antibody.

A) one
B) three
C) five
D) seven
E) twelve

Question 6

Epitopes or antigenic determinants

A) are parts of the antibody molecule.
B) are T cell receptors.
C) are parts of an antigen recognized by an antibody.
D) are B cell receptors.
E) are parts of an antibody recognized by an antigen.

Question 7

Which of the following molecules would be expected to be immunogenic?

A) Progesterone, a lipid hormone.
B) Serum albumin, a large protein.
C) Glucose, a simple sugar.
D) Linoleic acid, a fatty acid.
E) These are all equally immunogenic.

Question 8

Which of the following antibodies is a pentamer?

A) IgA
B) IgD
C) IgM
D) IgE
E) IgG

Question 9

The chains of an antibody molecule are bonded to one another by

A) disulfide bonds.
B) hydrogen bonds.
C) ionic bonds.
D) oxygen bonds.
E) ligases.

Question 10

A term synonymous with antibody is

A) antigen.
B) immunoglobulin.
C) epitope.
D) determinant.
E) immunotope.

Question 11

The scientist who received the first Nobel Prize in Medicine for his work on antibody therapy was

A) Koch.
B) von Behring.
C) Jenner.
D) Roux.
E) Pasteur.

Question 12

The immunoglobulin monomer consists of

A) four large chains.
B) two heavy and two light chains.
C) five light chains.
D) three heavy and three light chains.
E) one heavy and two light chains.

Question 13

Antibodies are made by

A) red blood cells.
B) macrophages.
C) B cells/plasma cells.
D) T cells.
E) all leukocytes.

Question 14

Which of the following antibodies is a dimer?

A) IgD
B) IgA
C) IgM
D) IgE
E) IgG

Question 15

Which class of antibody accounts for most of the circulating antibodies?

A) IgA
B) IgD
C) IgG
D) IgE
E) IgM

Question 16

Proteins that react specifically with the chemical structures in the antigen that induced them are called

A) determinants.
B) antibodies.
C) proteases.
D) macroproteins.
E) epitopes.

Question 17

Secondary lymphoid organs

A) facilitate interactions between cells.
B) are hematopoietic.
C) are the site of T cell maturation.
D) include the bone marrow and thymus.
E) are the site of B cell maturation.

Question 18

The characteristic function and properties of each class of antibody is determined by the

A) variable region on the light chains.
B) hinge region of all chains.
C) constant region on the light chains.
D) constant region on the heavy chains.
E) variable region on the heavy chains.

Question 19

Specific regions on an antigen molecule to which the immune response is directed are

A) antigenic determinants.
B) an autoimmune response.
C) monomers.
D) allergens.
E) antibody determinants.

Question 20

Which of the following do not induce a strong immune response?

A) Lipids
B) Proteins
C) Polysaccharides
D) Simple sugars
E) Lipids AND simple sugars.

Question 21

Each class of antibody is specifically defined by its

A) amino acid sequence of the constant region of the heavy chain.
B) amino acid sequence of the variable region of the light chain.
C) ability to cross the placenta.
D) presence of disulfide bonds.
E) ability to bind a range of antigens.

Question 22

Which is the first antibody class made during the primary response to an antigen?

A) IgA
B) IgM
C) IgG
D) IgE
E) IgD

Question 23

Which is the most efficient at initiating the classical pathway of the complement cascade?

A) IgA
B) IgD
C) IgM
D) IgE
E) IgG

Question 24

"Clonal selection" and "clonal expansion"

A) imply that each individual lymphocyte produces a single antibody.
B) describe how a single lymphocyte proliferates in a population of effector cells.
C) depend on an antibody recognizing a specific epitope.
D) explain how an antigen stimulates the production of matching antibodies.
E) All of the answer choices are correct.

Question 25

The only class of antibody that can cross the placenta is ________.

A) IgA
B) IgD
C) IgG
D) IgE
E) IgM

Question 26

The cells that actually secrete antibodies are

A) natural killer cells.
B) phagocytes.
C) plasma cells.
D) T cells.
E) naive B cells.

Question 27

The immunoglobulin that is important in hypersensitivity reactions is ________.

A) IgA
B) IgD
C) IgG
D) IgE
E) IgM

Question 28

T cells and B cells are produced in the

A) bone marrow.
B) thymus.
C) Peyer's patches.
D) nervous tissue.
E) appendix.

Question 29

The function of the secretory component of the IgA molecule is

A) to protect IgA from being destroyed by proteolytic enzymes.
B) to coat the antigen.
C) to facilitate opsonization.
D) to protect breast-fed infants against intestinal pathogens.
E) to protect IgA from being destroyed by lipases.

Question 30

CD4 cells are also known as 

A) T helper cells.
B) natural killer cells.
C) T cytotoxic cells.
D) macrophages.
E) neutrophils.

Question 31

The variable region of an antibody occurs

A) only on the heavy chains.
B) only on the light chains.
C) on one of the light chains.
D) on all four chains.
E) at the hinge region only.

Question 32

An IgG molecule has two

A) heavy chains, light chains, AND antibody binding sites.
B) heavy chains, light chains, AND antigen binding sites.
C) light chains, antigen binding sites, AND antibody binding sites.
D) antibody binding sites AND antigen binding sites.
E) Fc regions AND one Fab region.

Question 33

The Fc region on IgG

A) interacts with complement AND contains a variable region.
B) attaches to receptors on macrophages AND contains a variable region.
C) interacts with complement AND attaches to receptors on macrophages.
D) reacts with and coats the antigen AND interacts with complement.
E) reacts with and coats the antigen AND attaches to receptors on macrophages.

Question 34

According to the clonal selection theory

A) antibodies are modified, at the time of antigen exposure, to specifically react with the antigen.
B) self-reactive T cells are killed in the thymus.
C) B cells producing autoantibodies are eliminated in the thymus.
D) each B cell is already programmed to produce a specific antibody.
E) self-reactive T cells are killed in the thymus AND B cells producing autoantibodies are eliminated in the thymus.

Question 35

T cells mature in the

A) bone marrow.
B) thymus.
C) Peyer's patches.
D) nervous tissue.
E) tonsils.

Question 36

Which of the following is the most abundant immunological class produced?

A) IgA
B) IgD
C) IgG
D) IgE
E) IgM

Question 37

Ag-Ab binding may result in all of the following EXCEPT

A) neutralization.
B) immobilization.
C) agglutination.
D) opsonization.
E) fever.

Question 38

Antigens interact with antibodies at

A) the outer end of each arm of the Y.
B) the junction of heavy and light chains.
C) different regions depending on the class of antibody.
D) the bottom stem of the heavy chain of the Y.
E) the disulfide bridges of the antibody molecule.

Question 39

Which of the following class of antibody is primarily found in external secretions?

A) IgA
B) IgD
C) IgG
D) IgE
E) IgM

Question 40

How long after initiation of a primary response do significant amounts of antibody appear in the blood?

A) One day
B) 10-14 days
C) 4 weeks
D) 6 months
E) 48 hours

Question 41

Perforin is produced by

A) B cells.
B) macrophages.
C) NK cells.
D) T helper cells.
E) B cells AND NK cells.

Question 42

Macrophages and dendritic cells are

A) T cells.
B) B cells.
C) antigen-presenting cells.
D) antibody-producing cells.
E) lymphocytes.

Question 43

CD8 cells are

A) T helper cells.
B) natural killer cells.
C) T cytotoxic cells.
D) macrophages.
E) plasma cells.

Question 44

Class II MHC molecules are found primarily on

A) macrophages AND erythrocytes.
B) dendritic cells AND erythrocytes.
C) T cytotoxic cells AND dendritic cells.
D) macrophages AND dendritic cells.
E) T cytotoxic cells AND macrophages

Question 45

The stimulation of B cells to divide and mature is provided by

A) T helper cells.
B) macrophages.
C) T cytotoxic cells.
D) plasma cells.
E) erythrocytes.

Question 46

All antigens are immunogens.

Question 47

Giant cells are

A) a fusion of B cells.
B) a fusion of T cells.
C) used to contain bacterial infections.
D) activated T helper cells.
E) used to engulf very large pathogens.

Question 48

The immune response is directed against an entire molecule.

Question 49

Apoptosis

A) is a form of programmed cell death AND results specifically in T cell death.
B) is induced in target cells by effector T cytotoxic cells AND results specifically in T cell death.
C) results specifically in T cell death AND refers to the transformation of B cells into plasma cells.
D) is a form of programmed cell death AND is induced in target cells by effector T cytotoxic cells.
E) refers to the transformation of B cells into plasma cells.

Question 50

Which is involved in reacting to virus-infected cells?

A) B cells AND cell-mediated immunity 
B) MHC class II molecules, B cells AND cytotoxic T cells
C) B cells, leukocytes AND MHC class II molecules
D) MHC class I molecules, helper T cells AND humoral immunity
E) MHC class I molecules, cell-mediated immunity AND cytotoxic T cells

Question 51

IgA is the most abundant immunoglobulin made by the body.

Question 52

Antibody molecules are very rigid in structure.

Question 53

It would be useful if antigens were delivered directly to

A) Peyer's patches.
B) W Cells.
C) M cells.
D) red blood cells.
E) Peyer's patches AND M cells.

Question 54

The peptides presented by MHC class II peptide molecules are

A) from plasma cells.
B) exogenous antigens.
C) endogenous antigens.
D) from T helper cells.
E) antibodies.

Question 55

Which of the following does NOT form a memory population after activation and differentiation?

A) B cells.
B) T cytotoxic cells.
C) T helper cells.
D) Macrophages.
E) These all form memory cells.

Question 56

Only antigen-presenting cells

A) produce MHC class I molecules.
B) produce MHC class II molecules.
C) produce antibodies.
D) activate cytotoxic T cells.
E) activate regulatory T cells.

Question 57

T-independent antigens

A) include polysaccharides.
B) require the involvement of T cells.
C) interact with MHCI molecules.
D) are usually proteins.
E) include polysaccharides AND require the involvement of T cells.

Question 58

The surface receptors on B and T cells both

A) play the same role in each type of cell.
B) bind to free antigen.
C) have two binding sites for antigen.
D) have variable and constant regions.
E) play the same role in each type of cell AND bind to free antigen.

Question 59

Antigens may be processed for presentation by

A) macrophages AND erythrocytes.
B) dendritic cells AND erythrocytes.
C) erythrocytes, macrophages, AND dendritic cells.
D) T cytotoxic cells, B cells, AND dendritic cells.
E) macrophages, B cells, AND dendritic cells.

Question 60

Antibody and antigen are held to one another by covalent bonds.

Question 61

Identify the role(s) of natural killer cells.

A) Phagocytosis of virus infected cells AND production of cytokines that help regulate and direct certain immune responses.
B) Antibody-dependent cellular cytotoxicity AND negative selection of lymphocytes that recognize normal "self" molecules AND regulation and direction of certain immune responses.
C) Destruction of stressed host cells such as those infected with viruses AND negative selection of lymphocytes that fail to recognize normal "self" molecules.
D) Antibody-dependent cellular cytotoxicity OR destruction of stressed host cells such as those infected with viruses.
E) Regulation and direction of certain immune responses AND phagocytosis of virus infected cells AND stimulation of MHC class I molecules.

Question 62

What is a naive lymphocyte?

A) A lymphocyte that has an antigen receptor but has not yet encountered the antigen recognized by the receptor.
B) A lymphocyte that has encountered the antigen recognized by its receptor but has not yet made antibodies.
C) A lymphocyte that has encountered the antigen recognized by its receptor but has not yet made antibodies and cytokines.
D) A lymphocyte that has encountered the antigen recognized by its receptor but has not yet undergone apoptosis.
E) A lymphocyte that has not yet encountered the antigen recognized by its receptor but is making antibodies.

Question 63

Please select the CORRECT statement regarding MHC molecules.

A) Cytotoxic T cells recognize antigens presented on MHC class II molecules.
B) Dendritic cells are the only cells that make MHC class II molecules.
C) All nucleated cells express MHC class II molecules.
D) Helper T cells recognize antigens presented on MHC class II molecules.
E) Endogenous antigens are presented on MHC class II molecules.

Question 64

The best possible analogy available for the way in which variable (V), diversity (D), and joining (J) antibody gene segments get put together to create the diversity possible in hypervariable regions is

A) to think of the various segments as a deck of cards-when you get dealt a hand of five cards, you have a very high likelihood of getting a different hand every time. The quality of the hand you have dealt will dictate whether you have a "winning" hand (capable of binding to antigenic epitopes).
B) to think of the various segments as the pieces of a house-you need a strong foundation first (the joining segments), followed by a frame (the diversity segments), then the interior walls (the variable segments) before the structure is complete.
C) to think of the various segments as building a highway-you need to prepare the area first by clearing a path (the joining segments do this), then grade/slope the area (the diversity segments) before you can finally lay down the asphalt (the variable segments).
D) to think of the various segments as a bingo game-each segment is randomly selected, but you're going to need one of each (V, D, and J) to form a functional molecule. The "right" combination varies depending on which antigen is eventually going to be binding to the molecule (i.e., your bingo card would be the eventual antigen, and the random calling out of the number/letter combinations would be the forming of the VDJ hypervariable region).
E) to think of the various segments as the characters in a game of Clue. Each character is assigned a specific weapon with which to commit a murder (the joining segments), but once that is assigned, the room in which the murder occurs is random (the diversity segments); to get a complete picture, you need to know the name of the victim (variable segments).

Question 65

Why would a person who has their tonsils removed be more susceptible to certain types of infections of the throat and respiratory tract?

A) Tonsils are primary lymphoid organs found in the oral cavity that produce high levels of lactoferrin and transferrin; these are strong natural antibacterial compounds that protect the lungs.
B) Tonsils are secondary lymphoid organs found in the oral cavity that produce large amounts of interferons; these are natural antiviral compounds that protect the respiratory tract.
C) Tonsils are secondary lymphoid organs; they help to provide a constant response to the microbes in the oral cavity, helping to keep them in check and preventing them from spreading to other areas.
D) Tonsils are the location where T cells develop and mature. Without them, a person won't have T cells, and will be more likely to suffer from infections that would normally be eliminated by such cells.
E) Tonsils are primary lymphoid organs; they help to provide a constant response to the microbes in the gut, helping to keep them in check and preventing them from spreading to other areas.

Question 66

Which of the following is/are a(n) antigen-presenting cell(s)?

A) Macrophages
B) Dendritic cells
C) B cells
D) Macrophages, dendritic cells, AND B cells
E) Macrophages AND dendritic cells

Question 67

Please identify the incorrect definition.

A) Cytotoxic T cell-type of lymphocyte programmed to destroy infected or cancerous "self" cells.
B) Plasma cell-effector form of a B cell; it functions as an antibody-secreting factory.
C) T cell receptor-molecule on a T cell that enables the T cell to recognize a specific antigen.
D) MHC class II-molecules that cells use to present antigen to cytotoxic T cells.
E) Fab region-portion of an antibody molecule that binds to the antigen.

Question 68

T cells are responsible for directly manufacturing antibodies.

Question 69

T cell receptors are identical to antibodies.

Question 70

What would be an appropriate response if an antigen is presented on MHC class II molecules?

A) An effector CD4 cell activates the presenting cell.
B) An effector CD8 cell activates the presenting cell.
C) An effector CD4 cell kills the presenting cell.
D) An effector CD8 cell kills the presenting cell.
E) An effector CD8 cell activates a naive CD4 cell.

Question 71

Which of the following contribute to antibody diversity?

A) Gene rearrangement AND imprecise joining
B) Imprecise joining AND combinatorial associations
C) Imprecise joining AND negative selection
D) Gene rearrangement, imprecise joining AND combinatorial associations
E) Positive selection, negative selection AND gene rearrangement

Question 72

Which of the following is the definition of clonal selection?

A) The killing of antibody-coated target cells by natural killer cells, granulocytes, or macrophages.
B) The process in which a lymphocyte's antigen receptor binds to an antigen, allowing the lymphocyte to multiply.
C) The process that allows a B cell to change the antibody class it is programmed to make.
D) The immune response that protects the mucous membranes, which involves secretory IgA.
E) The generation of diversity in antigen specificity through rearrangement of gene segments.

Question 73

How is a T-cell receptor different from a B-cell receptor?

A) T-cell receptors must have antigen broken down inside a cell and presented to them by a major histocompatibility complex (MHC) molecule.
B) B-cell receptors must have antigen broken down inside a cell and presented to them by a major histocompatibility complex (MHC) molecule.
C) T-cell receptors are composed of four protein chains (pieces), while B-cell receptors are composed of only two chains.
D) T-cell receptors are eventually secreted into the bloodstream by activated T-cells, whereas B-cell receptors are not; they always stay with the B-cell.
E) B-cell receptors are composed of chains of amino acids, while T-cell receptors are composed of chains of carbohydrates.

Question 74

In opsonization with IgG, why would it be important that IgG react with the antigen BEFORE a phagocytic cell recognizes the antibody molecule?

A) If the IgG is bound to the phagocyte BEFORE opsonization, it would most likely be ingested by the phagocyte before it could bind to a pathogen (it would be "naked," so to speak).
B) Binding of IgG by phagocytes would block the antigen binding sites on the IgG molecules, preventing them from binding to the microbes.
C) Binding of IgG by phagocytes changes their conformation-and by changing their protein conformation, their antigen binding sites are changed and they can no longer recognize their specific antigenic epitopes.
D) Binding of antibody by phagocytes results in immediate release of protein-destroying enzymes to the outside of the cell. Since antibodies are proteins, they would be destroyed by these enzymes (and would then be unable to bind to their specific antigenic epitopes).

Question 75

How is the central portion of a T cell receptor complex functionally analogous to the center of the B cell receptor complex?

A) It has two protein chains, just like a B-cell receptor.
B) Both receptors bind epitopes (small amino acid sections of antigen molecules).
C) Both bind structures directly on the surface of microbes.
D) Both can be secreted from lymphocytes to bind to pathogens under certain situations.
E) Both have two heavy chains and two light chains.

Question 76

A scientist reports the isolation of a new blood-borne virus that completely shuts down presentation of viral epitopes on MHC molecules in the cells it infects. He produces an internet video describing the virus, claiming it will be indestructible by CD8+ cytotoxic T cells and will kill millions of people. The medical community quickly denounces the warning as irrelevant, and the whole thing is quickly forgotten. Why?

A) CD8+ T cells are not the cells that are responsible for killing virally infected cells. The scientist has confused the information. The medical community denounces the information so that people are not unnecessarily alarmed by the video.
B) While CD8+ T cells ARE important for eliminating a viral infection, they are not the ONLY things that can do so. Natural killer cells can kill virally infected cells that have shut down MHC antigen presentation, and interferons can assist in cleaning virally infected cells.
C) A blood-borne virus would not be capable of rapidly infecting millions of people, due to its difficult mode of transmission AND CD8+ T cells are not the cells that are responsible for killing virally infected cells. The scientist has confused the information. The medical community denounces the information so that people are not unnecessarily alarmed.
D) B cells would be primed right away to produce complement proteins to destroy the virus. This would prevent cells from being infected with it in the first place. The medical community denounces the scientist's video to prevent people from becoming alarmed.
E) While CD8+ T cells ARE important for eliminating a viral infection, they are not the ONLY things that are capable of doing so. Natural killer cells can kill virally infected cells that have shut down MHC antigen presentation, and interferons can assist in cleaning virally infected cells AND a blood-borne virus would not be capable of rapidly infecting millions of people, due to its difficult mode of transmission.

Question 77

T-independent antigens can activate B cells directly.

Question 78

What happens when a helper T cell is activated?

A) Two populations of cells are formed: helper T cells and cytotoxic T cells; the TH cells activate B cells and the TC  cells target virus-infected cells.
B) Two populations of cells are formed: memory TH cells and effector TH cells; the effector TH cells produce a variety of antibodies.
C) Two populations of cells are formed: memory TH cells and effector TH cells; the effector TH cells play a role in activating B cells.
D) Two populations of cells are formed: effector TH cells and effector TC cells; these work together to activate B cells and macrophages.
E) Activated TH cells produce cytokines that stimulate dendritic cells, converting them into antigen-presenting cells.

Question 79

Would a denatured antigen be expected to have the same epitopes as its native (non-denatured) counterpart? Why?

A) Yes; epitopes are just a sequence of amino acids in a row, so they do not change regardless of 3D shape of the protein molecule they lie within.
B) Yes; all proteins must be broken down into individual epitopes for presentation to B and T cells on MHC molecules, so each antigen protein MUST be denatured to yield ANY epitopes.
C) No; ALL epitopes are dependent on being in the proper original 3D conformation of the protein. Denaturing them would destroy them by destroying that conformation.
D) No; denaturing an antigen results in epitopes with a different amino acid sequence from those on an intact antigen, so they are not the same at all.  
E) Yes AND No; SOME epitopes are dependent on 3D conformation (conformational epitopes), while some simply depend on the sequence of amino acids (linear epitopes). So, really, it depends on the particular epitope.

Question 80

Gene rearrangement is responsible for the generation of the various antibody molecules.