Chapter 17

12) Which of the following is false about haptens?

a) A hapten alone cannot act as an antigen. b) A large protein (to which a hapten can bind) alone cannot act as an antigen. c) Only the combination of a hapten and a large protein can act as an antigen. d) Haptens bind to antibodies preventing them from binding to a large protein. Answer: d

4) Injection of a person with a vaccine that induces protective immunity in that individual is an example of what type of immunity?

a) Actively acquired natural immunity b) Innately acquired natural immunity c) Actively acquired artificial immunity d) Passively acquired natural immunity Answer: c

6) What is a substance that is recognized by the body as foreign and normally induces an immune response?

a) Antibody b) Antigen c) Agglutinin d) Antitoxin Answer: b

5) Colostrum, which contains high concentrations of antibodies passed onto an infant from a mother during breast-feeding, is an example of what type of immunity?

a) Artifically acquired active immunity b) Naturally acquired active immunity c) Naturally acquired passive immunity d) Artifically acquired passive immunity Answer: c

3) Injection of a patient with ready-made antibodies produced in a different host is an example of what type of immunity?

a) Artificially acquired active immunity b) Naturally acquired active immunity c) Naturally acquired passive immunity d) Artificially acquired passive immunity Answer: d

50) Which of the following pathogens is matched incorrectly with the immune response it elicits?

a) Bacteria - antibodies b) Viruses - NK cells and Tc cells c) Fungi - IgA antibodies and cell mediated responses d) Protozoa - humoral responses including opsonization and phagocytosis Answer: d

49) Which of the following is not a mechanism by which protozoa evade the immune response?

a) Cellular invasion b) Cyst formation c) Antigenic variation d) IgM activating enzymes Answer: d

36) Which region of an antibody determines the class of that particular antibody?

a) Constant b) Variable c) Light chain d) Fab Answer: a

7) An area on an antigen molecule to which an antibody molecule binds.

a) Fc fragment b) Fab fragment c) Fab and Fc fragment d) Epitope or antigenic determinant Answer: d

29) All of the following have correctly matched antibody class with their function except:

a) IgD - function largely unknown b) IgE - binds to mast cells and basophils c) IgM - plays a role in mediating allergies and asthma d) IgG - crosses placenta Answer: c

27) Which class of immunoglobulin consists of five units connected by J chains?

a) IgG b) IgA c) IgM d) IgE Answer: c

1) Which refers to the ability of a host organism to recognize and defend itself against the onslaught of pathogenic microorganisms?

a) Immunity b) Passive immunity c) Susceptibility d) Innate immunology Answer: a

47) Which of the following statements about immunization is false?

a) Inadequate refrigeration decreases effectiveness of measles vaccine b) Recommended age for immunization in children varies for each vaccine c) Injection of gamma globulin can establish passive immunization d) Route of administration does not affect the vaccine's efficacy Answer: d

33) Which of the following immune cells kills infected cells by releasing the lethal protein perforin?

a) NK cells b) B cells c) macrophages d) TH2 cells Answer: a

40) Which of the following T cells has CD8 receptors on its surface and recognizes virus-infected cells by viral antigens presented on macrophages?

a) NK cells b) TC cells c) TD cells d) TH cells Answer: b

39) Which of the following T cells is activated by interleukin-1 and in turn activates B cells to differentiate into plasma cells?

a) NK cells b) TC cells c) TD cells d) TH cells Answer: d

30) Monoclonal antibodies are all of the following except:

a) antibodies that are produced at greatest frequency in the body b) made by hydridomas which make only one specific antibody c) produced by a clone of cultured cells d) used for diagnostic tests and to treat rheumatoid arthritis Answer: a

21) After differentiation how do B cells migrate?

a) bone marrow blood circulation lymph nodes b) bone marrow thymus blood circulation c) bone marrow bursa of Fabricius lymph nodes d) lymph node bone marrow blood circulation Answer: a

15) What is the site where stem cells develop into B lymphocyte in humans?

a) bursa of Fabricius b) thymus gland c) blood d) bone marrow Answer: d

42) Mucosal immune system:

a) carries out immune responses in exactly the same manner as in the blood b) blocks bacterial replication but does not stimulate the adaptive immune system c) has IgE as its primary immunoglobulin on mucosal surfaces d) is the largest component of the immune system Answer: d

18) Immunity that is mediated by T lymphocytes is called _____.

a) cell-mediated b) antibody-mediated c) innate acquired d) innate natural Answer: a

22) The ability of the specific immune system to produce many identical B cells that recognize a specific antigen:

a) cross reaction b) clonal selection c) gamma globulin d) species immunity Answer: b

13) All of the following cells are types of T lymphocytes except:

a) cytotoxic b) delayed hypersensitivity c) helper d) plasma Answer: d

32) All of the following pertain to the role of activated helper T cells in cellular mediated immunity except:

a) differentiation into memory TC cells b) recognizes MHC with antigenic peptide on macrophages c) differentiation into TH1 cells d) differentiation into TH2 cells Answer: a

20) Both humoral and cellular immunity share the following attributes except:

a) distinguishes self from non-self b) specificity c) memory d) first-line of defense Answer: d

43) All of the following are environmental factors that modify the immune response in a host except:

a) genetics and age b) pollution and radiation c) tobacco smoke d) excessive exposure to radiation Answer: a

41) Privileged sites:

a) have M cells interspersed between epithelial cells b) include the uterus, anterior chamber of the eye and testes c) have especially strong immune responses against viruses d) are not accessible to most pathogens Answer: b

23) The process whereby lymphocytes which recognize self antigens are removed, thus producing tolerance in the host is:

a) heterogeneity b) memory c) primary response d) clonal deletion Answer: d

8) Antigens are found on:

a) human cells b) bacteria and viruses c) antibodies d) two of the above Answer: d

17) Immunity that is mediated by antibodies is called _____.

a) innate b) humoral c) cell-mediated d) non-specific Answer: b

37) Agglutination:

a) is inactivation of bacterial toxins due to the binding of an antibody b) leads to the ingestion of the particle by macrophages due to opsonization c) requires complement d) occurs when antibody-antigen complexes form large clumped particles Answer: d

45) All of the following are types of vaccines except:

a) killed whole bacteria b) purified active toxin c) toxoid d) live virus Answer: b

10) Most antigens are _____.

a) large and complex molecules b) polysaccharides c) are proteins with molecular weights less than 10,000 Da d) internal components of microbial cells Answer: a

48) All of the following statements about immunization are true except:

a) live vaccines are potentially hazardous to pregnant females b) passive immunization can provide immediate immunity to an exposed person c) vaccines need to be practical in terms of stability and use d) recombinant DNA vaccines inject the entire genomes of nonvirulent pathogens Answer: d

44) A compromised host _____.

a) may have a poor diet b) may have an impairment in cell mediated immunity but not humoral immunity c) usually has increased resistance to infectious diseases d) two of the above Answer: d

24) The ability of the humoral response to produce a vast array of antibodies, each with uniqueness to a given antigen, is called:

a) memory b) hyperimmune serum c) heterogeneity d) homogeneity Answer: c

16) Cells that are neither T nor B cells, but function to non-specifically kill cells infected by viruses are called:

a) natural killer cells b) phagocytic cells c) memory cells d) blood cells Answer: a

19) Programmed cell death is also known as _____.

a) necrosis b) mitosis c) meiosis d) apoptosis Answer: d

28) Antibodies produced by the humoral response help eliminate foreign antigens by all of the following ways except:

a) neutralization b) opsonization c) complement activation d) natural killer cell activation Answer: d

38) Hybridomas are used to produce _____.

a) opsonization b) membrane attack complex c) monoclonal antibodies d) polyclonal antibodies Answer: c

9) A protein molecule produced in a host in response to an antigen which is capable of binding specifically to that antigen is a/an:

a) perforin b) antigen c) antibody d) cytokine Answer: c

14) Cells that synthesize and release antibody molecules are:

a) plasma cells b) stem cells c) cytotoxic T lymphocytes d) helper T lymphocytes Answer: a

35) The role of activated macrophages is to:

a) produce polyclonal antibodies b) produce toxic hydrogen peroxide and accelerate the inflammatory response c) bind to the MHC II molecule and T cell receptor molecule not in the receptor site d) none of the above Answer: b

31) Activated delayed hypersensitivity T (TD) cells:

a) release macrophage chemotactic factor b) play a role in humoral immunity c) suppress T cells d) release perforin molecules Answer: a

46) All are hallmarks of an effective vaccine except:

a) safe and stable b) no adverse side effects c) sustained protection d) should generate antibodies but not T cells Answer: d

34) Antigens that have the capacity to activate huge numbers of immune T cells non-specifically resulting in a large immune response that results in diseases are _____.

a) self antigens b) non-self antigens c) superantigens d) antitoxins Answer: c

2) Adaptive immunity is _____.

a) the ability of a host to mount a defense against a specific inherited agent b) only acquired artificially c) only acquired naturally d) immunity obtained in some manner other than by heredity Answer: d

11) The concentration of antibody needed to bind to and neutralize an antigen is called the:

a) tolerance b) toxicity c) titer d) antitoxin Answer: c

26) All of the following correctly describe the structure of an antibody molecule except:

a) two identical light chains b) heavy and light chains held together by disulfide bonds c) binds 2 antigens per molecule d) two Fc fragments and one Fab fragment Answer: d

25) Cross reactions occur in all of the following cases except:

a) when an antibody reacts with structurally similar antigens b) when syphilis has the same antigens as human cells c) between a hapten and a carrier molecule d) recognition of two strains of bacteria Answer: c