chapter 13

Antitoxins ________. A) contain modified bacterial exotoxin molecules B) are always genetically engineered C) contain select antigenic components of a pathogen rather than whole cells or viruses D) confer passive immunity E) utilize DNA strands that will produce the antigen

D

B cell-receptors differ from T cell-receptors in that ________. A) B cell-receptors are comprised of four polypeptides, whereas T cell-receptors are made up of two polypeptides B) B cell-receptors are immunoglobulins similar to those that are secreted, whereas T cell-receptors are not immunoglobulins and are never secreted C) T cell-receptors are much smaller than B cell-receptors D) All of the choices reflect differences between B cell- and T cell-receptors.

D

Class II MHC genes code for ________. A) certain secreted complement components B) self receptors recognized by T lymphocytes C) all HLA antigens D) receptors located primarily on macrophages and B cells E) All of the choices are correct.

D

Edward Jenner's work involved ________. A) inoculation of dried pus from smallpox pustules into a person to stimulate immunity B) development of passive immunotherapy C) development of an immunization to protect people against cowpox D) immunization using a related, less pathogenic organism to give protection against a more pathogenic one E) All of the choices are correct.

D

MHC molecules are found on each of the following cells except ________. A) leukocytes B) eosinophils C) epithelial cells D) red blood cells E) islet of Langerhans cells

D

Properties of effective antigens include all the following except ________. A) are foreign to the immune system B) have molecular complexity C) are large molecules with a minimum molecular weight of 1,000 D) have large polymers made up of repeating subunits E) are cells or large, complex molecules

D

The benefit of specific immunity is the production of ________ that provide long-lasting protection. A) antibodies B) plasma cells C) T helper cells D) memory cells E) phagocytotic cells

D

The immunoglobulin class that is the only one capable of crossing the placenta is ________. A) IgA B) IgD C) IgE D) IgG E) IgM

D

Which immunoglobulin class(es) can fix complement? A) IgM only B) IgG only C) IgD only D) IgM and IgG E) IgE and IgA

D

Which process involves antibodies cross-linking cells or particles into large aggregates? A) Neutralization B) Opsonization C) Complement fixation D) Agglutination E) Anamnestic response

D

An example of natural active immunity would be ________. A) chickenpox infection followed by lifelong immunity B) chickenpox vaccine, which triggers extended immunity to chickenpox C) giving a person immune serum globulins to chickenpox virus after exposure to the disease D) a fetus acquiring maternal IgG to the chickenpox virus across the placenta E) None of the choices are correct.

A

Destruction of lymphocytes with self specificity is called ________. A) clonal deletion B) proliferation C) clonal selection D) differentiation E) hypersensitivity

A

During which response to the antigen do we display a latent period of no secretory antibody synthesis? A) Primary B) Secondary C) Tertiary D) Quaternary E) Memory response

A

Gamma-delta T cells differ from other T cells in that ________. A) they can be directly activated by PAMPs, whereas other T cells have to be presented with the antigen in conjunction with an MHC molecule on an antigen-presenting cell B) they do not have T cell-receptors to bind to antigens C) they do not produce memory cells, unlike the T helper and T cytotoxic cells D) they can react against cancer cells, whereas the other T cells can only target bacteria and viral-infected cells

A

Herd immunity involves ________. A) maintaining a certain level of immunized individuals in a society to prevent a pathogen from circulating through the population B) keeping bovine diseases to a minimum so they do not spread to the human population C) encouraging individuals to work and live in close proximity to each other to prevent spread of a disease outside of a population D) maintaining a 100% vaccination rate among farm workers to prevent the spread of zoonotic diseases

A

High titers of specific antibodies are components of ________. A) specific immune globulin (SIG) B) gamma globulin C) immune serum globulin (ISG) D) attenuated vaccines E) toxoids

A

In addition to dendritic cells and macrophages, B cells can also act as antigen-presenting cells. This occurs when ________. A) the antigen is a molecule with a simple, repeating structure and evokes an immune response as a T-cell-independent antigen B) the B cell engulfs the antigen and presents it to the T helper cell C) the B cell engulfs the antigen and presents it to the T cytotoxic cell D) the antigen binds to the B cell and after processing, it is presented to the dendritic cells and macrophages

A

Which of the following is not a target for TC cells? A) Bacteria B) Virus-infected cells C) Cancer cells D) Human transplanted liver E) Pig transplanted heart

A

Which of the statements below represents the correct order in the development of an immune response? A) Development and clonal deletion; antigen presentation; lymphocyte challenge; lymphocyte response B) Antigen presentation; development and clonal deletion; lymphocyte challenge; lymphocyte response C) Lymphocyte challenge; antigen presentation; development and clonal deletion; lymphocyte response D) Development and clonal deletion; lymphocyte challenge; antigen presentation; lymphocyte response

A

Which process involves antibodies covering surface receptors on a virus or toxin molecule thereby disrupting their activity? A) Neutralization B) Opsonization C) Complement fixation D) Agglutination E) Anamnestic response

A

Which statement is true regarding lymphocyte specificity? A) Genetic rearrangement in the DNA that codes for antigen receptors results in up to 10 trillion permutations in the variable regions of B- and T lymphocyte-receptors. B) There is a different gene for every possible antigen that a lymphocyte may encounter. C) B lymphocytes have specificity for a large number of different antigens, however T lymphocytes can recognize only 500 antigens corresponding to the number of gene segments that code for the antigen receptors. D) B- and T cell-receptors are identical and both recognize up to 500 antigens corresponding to the gene segments that code for the antigen receptor variable regions.

A

________ is the most abundant class of antibodies in serum. A) IgG B) IgM C) IgA D) IgD E) IgE

A

A foreign molecule that causes a specific immune response is a(n) ________. A) PAMP B) marker C) hapten D) antibody E) antigen

E

A naive B lymphocyte has receptors bound to its surface that ________. A) are all specific for the same antigen B) have a variable region that is different to the variable regions of B cell-receptors embedded in other naive B lymphocytes C) is one of up to 10 trillion possible protein configurations due to genetic rearrangement D) will have the same variable region as the antibodies that will be secreted following a challenge by the corresponding antigen E) All of the choices are true statements concerning B lymphocyte-receptors.

E

All of the following are characteristics of IgM except ________. A) has 10 antigen binding sites B) contains a central J chain C) is the first class synthesized by a plasma cell D) can serve as a B-cell receptor E) is a dimer

E

Antigen-presenting cells ________. A) include dendritic cells B) include macrophages C) engulf and modify antigen to be more immunogenic D) hold and present processed antigen on their cell membrane surface E) All of the choices are correct.

E

Cell surface markers involved in immune reactions ________. A) are the result of genetic expression B) function in recognition of self molecules C) receive and transmit chemical messages among other cells of the system D) aid in cellular development E) All of the choices are correct.

E

Gamma-delta T cells ________. A) are considered a bridge between nonspecific and specific immune responses B) have T cell-receptors that target a wide range of antigens C) can bind to, and become activated by PAMPs D) differentiate into memory cells E) All of the choices are true.

E

Helper T cells ________. A) secrete antibodies B) function in allergic reactions C) directly destroy target cells D) suppress immune reactions E) activate B cells and other T cells

E

Immunotherapy is the ________. A) use of antitoxins B) use of immune serum globulin C) conferring of passive immunity D) administering of preformed antibodies E) All of the choices are correct

E

Lymphocyte maturation involves ________. A) hormonal signals that initiate development B) B cells maturing in bone marrow sites C) T cells maturing in the thymus D) release of mature lymphocytes to begin migration to various lymphoid organs E) All of the choices are correct.

E

Lymphocytes ________. A) possess MHC antigens for recognizing self B) have membrane receptors that recognize foreign antigens C) gain tolerance to self by destruction of lymphocytes that could react against self D) develop into clones of B and T cells with extreme variations of specificity E) All of the choices are correct.

E

T-cell response to T-cell-dependent antigens requires ________. A) typically a protein antigen B) binding of T-cell to a class II MHC receptor on a macrophage C) binding of T-cell to a site on the antigen D) interleukin-1 activating the T helper cell E) All of the choices are correct.

E

To exhibit high immunogenicity, an antigen would preferably________. A) originate in another organism B) be large in size C) have chemical complexity D) have cell surface markers not recognized as self E) All of the choices are features of a good antigen.

E

Which lymphocytes lack specificity for antigen and are cells that attack cancer cells and virus-infected cells? A) Helper T cells B) Suppressor T cells C) Cytotoxic T cells D) Delayed hypersensitivity T cells E) Natural killer (NK) cell

E

Which process involves a more rapid synthesis and greatly increased titer of antibody when the immune system is subsequently exposed to the same antigen? A) Neutralization B) Opsonization C) Complement fixation D) Agglutination E) Memory response

E

Acquired specific immunity involves the response of ________. A) skin barriers B) B and T lymphocytes C) lysozyme D) mucous membranes E) interferon

B

An activated TH cell produces ________, which is a growth factor for T helper cells and cytotoxic T cells. A) interleukin-1 B) interleukin-2 C) interleukin-12 D) antiserum E) complement

B

An example of artificial active immunity would be ________. A) chickenpox infection followed by lifelong immunity B) chickenpox vaccine which triggers extended immunity to chickenpox C) giving a person immune serum globulins to chickenpox virus after exposure to the disease D) a fetus acquiring maternal IgG to the chickenpox virus across the placenta E) None of the choices are correct.

B

Class I MHC genes code for ________. A) certain secreted complement components B) self receptors recognized by T lymphocytes C) all HLA antigens D) receptors located primarily on macrophages and B cells E) All of the choices are correct.

B

Each ________ fragment of an antibody molecule contains the variable regions of a heavy and light chain that folds into a groove for one epitope. A) variable B) Fab C) Fc D) terminal E) hinge

B

The major histocompatibility complex is ________. A) glycoproteins, called MHC antigens, found on all body cells B) a set of genes that code for MHC glycoproteins C) found on the third chromosome D) located in the thymus gland E) All of the choices are correct.

B

Which is incorrect about the Fc region of an immunoglobulin? A) Is called the crystallizable fragment B) Forms the antigen binding sites C) Contains an effector molecule that can bind to cells such as macrophages and mast cells D) Contains an effector molecule that can fix complement E) Determines the class to which the immunoglobulin belongs

B

Which process involves antibodies coating microorganisms in order to facilitate phagocytosis? A) Neutralization B) Opsonization C) Complement fixation D) Agglutination E) Anamnestic response

B

Acellular vaccines and subunit vaccines ________. A) contain modified bacterial exotoxin molecules B) are always genetically engineered C) contain select antigenic components of a pathogen rather than whole cells or viruses D) confer passive immunity E) utilize DNA strands that will produce the antigen

C

An example of artificial passive immunity would be ________. A) chickenpox infection followed by lifelong immunity B) chickenpox vaccine which triggers extended immunity to chickenpox C) giving a person immune serum globulins to chickenpox virus after exposure to the disease D) a fetus acquiring maternal IgG to the chickenpox virus across the placenta E) None of the choices are correct.

C

Antigens that elicit allergic reactions are called ________. A) superantigens B) heterophilic antigens C) allergens D) autoantigens E) None of the choices are correct

C

Cytotoxic T cells ________. A) are directly activated by antigens B) lack specificity for antigen. C) secrete granzymes and perforins that damage target cells D) secrete interleukin-2 to stimulate B and T cells E) All of the choices are correct.

C

During presentation of APC-bound antigen, macrophages and dendritic cells secrete the cytokine, ________, that activates T helper cells. A) interferon B) interleukin-2 C) interleukin-1 D) histamine E) None of the choices are correct.

C

Superantigens are ________. A) body tissues that the immune system mistakes as foreign B) cell markers found in some member of a species but not in other members C) bacterial toxins that activate T cells at a 100 times greater rate than other antigens D) those that evoke allergic reactions E) None of the choices are correct.

C

The immunoglobulin class that has an Fc region that binds to receptors on basophils and mast cells is ________. A) IgA B) IgD C) IgE D) IgG E) IgM

C

The most significant cells in graft rejection are ________. A) helper T cells B) suppressor T cells C) cytotoxic T cells D) delayed hypersensitivity T cells E) natural killer (NK) cells

C

What are the risks to society when herd immunity is not maintained? A) Decreasing antibody titers in individuals require booster shots which restricts the number of available vaccines. B) Cattle become increasingly more susceptible to dangerous pathogens, which can spread to humans. C) Dangerous pathogens can reemerge and outbreaks of diseases may develop. D) There are no risks to society when herd immunity is not maintained; it is a precautionary measure only.

C

What process provides many B cells and T cells that are activated against specific antigens? A) Antigen expression B) Antibody production C) Clonal expansion D) Antigen presentation E) Opsonization

C

What type of cells secrete antibodies? A) B cells B) Cytotoxic T cells C) Plasma cells D) Helper T cells E) Antigen-presenting cells

C

Which of the following is not a property of B cells? A) Produce plasma cells and memory cells B) Low numbers circulating in the blood C) Require antigen presented with MHC proteins D) Receptors called immunoglobins E) Mature in the bone marrow

C

Antibodies directed to alloantigen from one organism often cross-react with an alloantigen from another organism. T/F

T

Clonal selection can be stimulated by foreign or self antigens. T/F

T

Gamma globulin can be given as immunotherapy to confer artificial passive immunity. T/F

T

One plasma cell will secrete antibodies of various classes but the antibodies will all have the same specificity. T/F

T

The diversity and specificity of the lymphocyte repertoire against any potential antigen it may encounter is due to the rearrangement of gene segments that code for the antigen receptors. T/F

T

The secondary response to an antigen is faster and bigger than the primary response. T/F

T

The structural and functional differences that distinguish immunoglobulin isotypes are due to variations associated with their Fc fragments. T/F

T

Vaccinating a child against a dangerous pathogen not only protects that child from disease, but it also protects society as a whole, since herd immunity in the population is maintained. T/F

T

All nucleated cells contain ________. A) class I MHC B) class II MHC C) secretory antibodies D) IgE receptors E) IgM molecules

A

The immunoglobulins found on the surface of B cells are ________. A) IgM only B) IgG only C) IgD only D) IgM and IgD E) IgD and IgE

D

The monomer subunit of immunoglobulin molecules has all the following except ________. A) two identical heavy polypeptide chains B) two identical light polypeptide chains C) disulfide bonds between polypeptide chains D) four antigen binding sites E) a variable and constant region on each polypeptide chain

D

The progeny cells of a B-cell clone are called ________. A) antibodies B) sensitized T cells C) activated macrophages D) plasma cells E) bursa cells

D

) Live, attenuated vaccines ________. A) include the Sabin polio vaccine B) include the measles, mumps, rubella vaccine (MMR) C) contain viable microbes that can multiply in the person D) require smaller doses and fewer boosters compared to inactivated vaccines E) All of the choices are correct

E

After secreting antibodies during an immune response, plasma cells then differentiate into memory cells. T/F

F

Antibody molecules circulate in lymph, blood, and tissue fluids. T/F

T

Plasma cells ________. A) secrete antibodies B) function in allergic reactions C) directly destroy target cells D) suppress immune reactions E) activate B cells and other T cells

A

The histocompatibility complex proteins function in ________. A) recognition of self B) antibody proliferation C) B-cell maturation D) T-cell maturation E) None of the choices are correct.

A

The immunoglobulin class that has a dimer form found in mucus, saliva, colostrum, and other body secretions is ________. A) IgA B) IgD C) IgE D) IgG E) IgM

A

The importance of clonal deletion is that ________. A) lymphocytes with receptors that recognize self markers are eliminated to preserve immune tolerance B) worn-out lymphocytes are destroyed to make way for new cells C) lymphocytes that have been activated during antigen exposure are then removed when the individual recovers D) clones of cells that have the same receptor are deleted to avoid redundancy

A

The molecular fragment on an antigen molecule that a lymphocyte recognizes and responds to is called a(n) ________. A) epitope B) hapten C) antigen binding site D) variable region E) None of the choices are correct

A

The region of each antibody molecule where amino acid composition is highly varied from one clone of B lymphocytes to another is the ________. A) variable region B) joining region C) constant region D) light region E) hinge region

A

When an antibody is covering a foreign microorganism, complement may be activated via the ________ pathway. A) classical B) lectin C) alternative D) interleukin

A

Which of the following is a special binding substance that enhances immunogenicity and prolongs antigen retention at the injection site? A) Adjuvant B) Booster C) Antibodies to toxin D) Gamma globulin E) "Trojan horse" recombinant vaccine

A

Which of the following statements is false regarding the development of specific immunity? A) The fourth stage of specific immunity involves the production of antibodies by B and T cells against the antigen that initiated the response. B) The second stage in the development of specific immunity requires the antigen to be presented to the T cells on the surface of an APC. C) During the third stage in the development of specific immunity, B and T cells are challenged by the antigen and respond by differentiating and proliferating. D) The initiation of specific immunity involves the development of lymphocytes with the deletion of cells that would react to self molecules.

A

B cell-receptors are similar to T cell-receptors in that ________. A) both receptors are similar in size B) both receptors have a variable and a constant region C) both receptors can be secreted in response to antigen D) both receptors are comprised of four polypeptide chains E) All of the choices reflect similarities between B cell- and T cell-receptors.

B

Killed or inactivated vaccines are prepared by ________. A) removal of virulence genes from the microbe B) treatment with formalin, heat, or radiation C) passage of the pathogen through unnatural hosts or tissue culture D) long-term subculturing of the microbe E) All of the choices are correct

B

Small foreign molecules that are too small by themselves to elicit an immune response are termed ________. A) epitope B) hapten C) antigen binding site D) variable region E) None of the choices are correct.

B

An example of natural passive immunity would be ________. A) chickenpox infection followed by lifelong immunity B) chickenpox vaccine which triggers extended immunity to chickenpox C) giving a person immune serum globulins to chickenpox virus after exposure to the disease D) a fetus acquiring maternal IgG to the chickenpox virus across the placenta E) None of the choices are correct.

D

Human B lymphocytes mature in an intestinal region called the bursa. T/F

F

The hinge region of an antibody has a hypervariable amino acid region where the antigenic determinant fits. T/F

F

The third line of defense can be summarized in four stages; I—antigen binding to T helper cells, II—antigen binding to B cells, III—phagocytosis of antigen by B and T lymphocytes, IV—killing of antigen. T/F

F

To be an effective antigen, a molecule would ideally be small, and consist of repeating units with similar structure, such as a trisaccharide. T/F

F

Activation of B cells occurs when antigen binds to B-cell surface immunoglobulin receptors. T/F

T