51) A child develops symptoms of chicken pox, produces antibodies against its specific antigens, and recovers from the illness. Later as an adult, he is immune to another exposure to the chicken pox virus. This is an example of which type of immunity?

A) artificially induced active immunity

B) naturally acquired passive immunity

C) artificially induced passive immunity

D) innate (nonspecific) immunity

E) naturally acquired active immunity

52) In artificially induced active immunity,

A) exposure to an antigen in the environment occurs naturally.

B) antibody production is stimulated under controlled conditions so that the body makes a memory of the attack.

C) the body receives antibodies produced by another person.

D) antibodies are administered to prevent disease after exposure to the pathogen.

E) genes for antibodies are introduced into the body.

53) A virus is injected into a rabbit and the rabbit is allowed to make antibodies against the viral antigen. These antibodies are then removed from the rabbit plasma and injected into a human to combat an infection by the same virus. This would be an example of

A) innate immunity.

B) artificially induced passive immunity.

C) artificially induced active immunity.

D) naturally acquired passive immunity.

E) naturally acquired active immunity.

54) Blocking the antigen receptors on the surface of lymphocytes would interfere with

A) phagocytosis of the antigen.

B) that lymphocyte’s ability to produce antibodies.

C) antigen recognition.

D) the ability of the lymphocyte to present antigen.

E) agglutination of the antigen.

55) A version of the seasonal flu vaccine contains antibodies, which were produced against the previous season’s flu strain. When a person receives such a vaccine, which type of immunity is conferred?

A) naturally acquired active immunity

B) artificially induced active immunity

C) innate (nonspecific) immunity

D) naturally acquired passive immunity

E) artificially induced passive immunity

56) The major histocompatibility complex (MHC)

A) kills the target cell by disrupting its metabolism.

B) produces antibodies in lymph glands.

C) is a group of genes that codes for CD4 markers.

D) is a membrane protein that can display foreign antigens.

E) is the antigen found on bacteria that stimulates an immune response.

57) Cells that secrete substances, which coordinate specific and nonspecific defenses, are called

A) B cells.

B) plasma cells.

C) helper T cells.

D) cytotoxic cells.

E) NK cells.

58) Cytotoxic T cells destroy their target cells by releasing substances that

A) increase protein production.

B) enhance ribosomal activities.

C) suppress the antigen recognition process.

D) rupture cell membranes.

E) produce memory T cells.

59) Choose the correct paired interaction in order for T cell activation to occur.

A) CD8 T cells; Class I MHC proteins

B) CD4 T cells; Class I MHC proteins

C) CD8 T cells; Class II MHC proteins

D) CD6 T cells; Class I MHC proteins

E) CD6 T cells; Class II MHC proteins

60) Choose the most accurate characteristic of Class II MHC proteins.

A) They dampen the responses of other T cells and of B cells.

B) They divide to produce memory cells and more active helper T cells.

C) They are found in the plasma membranes of all nucleated cells.

D) They consist of circulating proteins that assist antibodies in the destruction of pathogens.

E) They are found in the membranes of lymphocytes and antigen-presenting cells.