Mastering Biology Chapter 43

For the successful development of a vaccine to be used against a pathogen, it is necessary that ________. A.)the surface antigens of the pathogen stay the same B.)the major histocompatibility (MHC) molecules are heterozygous C.)the pathogen has only one epitope D.)all of the surface antigens on the pathogen be identified

A

How does an antihistamine reduce allergy symptoms? A.)An antihistamine blocks receptors for inflammatory chemicals released from granules within mast cells. B.)An antihistamine binds pollen antigens, preventing them from provoking an allergic reaction. C.)An antihistamine kills mast cells, blocking an allergic reaction.

A

The role of active cytotoxic T cells is to attack _____. A.)body cells that have been infected B.)complement proteins C.)circulating proteins D.)circulating antibodies E.)extracellular viruses and bacteria

A

Which of the following statements best describes the role of mast cells in the inflammatory response? A.)They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream. B.)They release cytokines to stimulate the release of additional neutrophils and macrophages. C.)They secrete substances that degrade bacterial cell walls and engulf and digest the invaders. D.)They release chemicals that constrict blood vessels at some distance from the wound site.

A

Which of these cells is responsible for the rapidity of the secondary immune response? A.)memory cells B.)macrophages C.)plasma cells D.)cytokines E.)cytotoxic T cells

A

A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over 20 years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell? A.)thyroid cell B.)memory cell C.)plasma cell D.)macrophag

B

Acidity in human sweat is an example of _____. A.)acquired immunity B.)innate immunity C.)cell-mediated immune responses D.)adaptive immunity

B

Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____. A.)helper T cells ... plasma cells B.)B cells ... plasma cells and memory cells C.)B cells ... macrophages D.)T cells ... B cells E.)macrophages ... B cells and T cells

B

How do cells involved in the innate immune response detect the presence of pathogens? A.)Antibodies bind to the pathogens. B.)Leukocytes recognize unique molecules on pathogens. C.)Leukocytes recognize the entire pathogen. D.)Leukocytes recognize the secretions from a pathogen.

B

What is the role of recombinase in generating lymphocyte diversity? A.)Recombinase splices RNA to produce variable transcripts. B.)Early in B cell development, recombinase links one light-chain V gene segment to one J gene segment. C.)Recombinase combines DNA from human and viral origin.

B

An antigen _____. A.)is a protein molecule that helps defend the body against disease B.)is a protein attacked by an invading microorganism C.)could be an invading bacterium D.)is a foreign molecule that evokes a specific response by a lymphocyte E.)induces development of white blood cells in the bone marrow

C

Helper T cells are part of _____. A.)the complement system B.)a group of phagocytic white blood cells C.)cell-mediated immune responses D.)innate immunity E.)the first cells to bind to antigens

C

Innate immunity ________. A.)depends on an infected animal's previous exposure to a pathogen B.)is found only in vertebrates C.)is the first, and most general, mechanism of protection against pathogens D.)is based on recognition of antigens that are specific to a pathogen

C

The cells and signaling molecules involved in the initial stages of the inflammatory response are ________. A.)phagocytes and cytokines B.)lymphocytes and interferons C.)mast cells and histamines D.)dendritic cells and interferons

C

The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response. A.)antibodies ... antibody-mediated B.)interleukin-2 ... humoral C.)perforin ... cell-mediated D.)perforin ... humoral E.)antibodies ... humoral

C

Which of the following events occurs first when a wound that breaks the skin has occurred? A.)Macrophages present bacterial proteins as antigens on their plasma membrane. B.)Mast cells secrete chemical messengers to regulate blood flow to the wound. C.)Platelets release proteins that form clots and decrease bleeding. D.)Neutrophils secrete substances that degrade bacterial cell walls.

C

Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium? A.)cytotoxic T cell B.)helper T cell C.)macrophage D.)plasma cell E.)B cell

C

Which secretion is not a barrier that prevents pathogens from entering the body? Hints A.)Mucus. B.)Ear wax. C.)Antigens. D.)Lysozyme.

C

_____ interact with the antigen-class II MHC complex presented by macrophages. A.)B cells B.)Bacterial cells C.)Helper T cells D.)Cytotoxic T cells E.)Epithelial cells

C

Cell-mediated immunity differs from humoral immunity in that _____. See Concept 43.3 ( page 965) Hints A.)clonal selection occurs only in cell-mediated immunity B.)cell-mediated immunity is longer lasting C.)a humoral response is mounted more quickly D.)they respond differently to invaders E.)a subsequent secondary immune response can occur in humoral immunity

D

Clonal selection is an explanation for how ________. A.)macrophages can recognize specific T cells and B cells B.)HIV (human immunodeficiency virus) can disrupt the immune system C.)V, J, and C gene segments are rearranged D.)an antigen can provoke production of high amounts of specific antibodies

D

How is a viral antigen, like EBV, recognized by T cells? A.)Interferon proteins stick to the surface of infected cells. B.)T cells recognize antibodies that have bound to viral particles. C.)The virus is engulfed by T cells using Toll-like receptors. D.)An antigen fragment is presented within class I MHC to the T cell receptor.

D

Immunological memory accounts for _____. A.)the ability of a helper T cell to signal B cells via cytokines B.)the human body's ability to distinguish self from non-self C.)the observation that some strains of the pathogen that causes dengue fever cause more severe disease than others D.)the ancient observation that someone who had recovered from the plague could safely care for those newly diseased

D

The fact that there are about a million different antigen receptors possible in human B cells is based on _____. See Concept 43.2 ( page 956) Hints A.)having one million different immunoglobulin genes B.)temporary changes in the ways that RNA is spliced in the B cells C.)the capacity of memory cells to produce antibodies D.)constant changes in the splicing pattern of receptor genes after the differentiation of the B cell E.)recombination of the segments of the receptor DNA that make up the functional receptor genes of differentiated B cells

D

Which of the following cells can engulf a pathogen? A.)Platelets. B.)Mast cells. C.)Cytokines. D.)Macrophages.

D

Which of these cells produce and secrete antibodies? A.)macrophages B.)cytotoxic T cells C.)helper T cells D.)plasma cells E.)bacterial cells

D

B cells that have been stimulated by interleukin-2 develop into _____. A.)macrophages B.)helper T cells C.)cytotoxic T cells D.)antigens E.)plasma cells

E

True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils. True False

False

Vertebrate immune cells, which are phagocytic, include ________. I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells

I,II, and III

Which of the following statements are fundamental to the clonal-selection theory of how the adaptive immune system functions? I) Each lymphocyte has a unique membrane receptor that recognizes one antigen. II) When the lymphocyte binds an antigen, it is activated and begins dividing to form many identical copies of itself. III) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen. IV) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated.

I,II, and IV

Lymphocytes mature in the _____. I) spleen II) thymus III) bone marrow

II and III

The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors. True False

True

A third exposure to antigen X will produce an even stronger immune response than the second exposure did.

can not be determined from the graph

The primary immune response takes about 28 days to reach its peak.

not supported

The primary immune response to antigen X occurred just as fast as the secondary immune response to antigen X.

not supported

The secondary immune response is stronger than the primary immune response.

supported