Deck 35: The Immune System

Question 1

Engulfing-phagocytic cells of innate immunity include all of the following except

A)neutrophils.
B)macrophages.
C)dendritic cells.
D)natural killer cells.

Answer 1

D

Question 2

Salmonella are a genus of pathogenic bacteria that can cause infections through the gastrointestinal tract.How could Salmonella poisoning be initiated if a human were to ingest these bacteria?

A)The bacteria survive the acidic environment of the stomach and resist lysosomal degradation in macrophages.
B)There is a delay in selection of the population of eosinophils that recognize and fight these bacteria.
C)The bacteria release chemical messengers that make them resistant to phagocytosis.
D)The combination of foods eaten at a meal increases the pH of the stomach sufficiently so that ingested bacteria are not destroyed.

Answer 2

A

Question 3

Acidity in human sweat is an example of

A)cell-mediated immune response.
B)acquired immunity.
C)adaptive immunity.
D)innate immunity.

Answer 3

D

Question 4

The complement system is a

A)set of proteins involved in innate but not acquired immunity.
B)set of proteins secreted by cytotoxic T cells and other CD8 cells.
C)group of proteins that includes interferons.
D)group of antimicrobial proteins that act together in a cascading manner.
E)set of proteins that act individually to attack and lyse microbes.

Question 5

Histamines trigger dilation of nearby blood vessels as well as an increase in vessel permeability,producing

A)redness and heat only.
B)swelling only.
C)pain only.
D)redness,heat,and swelling.

Question 6

A systemic inflammatory response that is often life-threatening is

A)mild fever.
B)aches and dull pain.
C)septic shock.
D)high blood pressure.
E)increased white blood cell count.

Question 7

The eyes and the respiratory tract are both protected against infections by

A)the mucous membranes that cover their surface.
B)the secretion of complement proteins.
C)the release of slightly alkaline secretions.
D)the secretion of lysozyme onto their surfaces.
E)interferons produced by immune cells.

Question 8

Suppose that a mosquito has been internally infected by a potentially pathogenic fungus.What will help protect it from the infection?

A)its plasma cells
B)its immunoglobulins
C)its antibodies
D)its antimicrobial peptides
E)its B cells

Question 9

Inflammatory responses typically include

A)clotting proteins migrating away from the site of infection.
B)increased activity of phagocytes in an inflamed area.
C)reduced permeability of blood vessels to conserve plasma.
D)release of substances to decrease the blood supply to an inflamed area.
E)inhibiting the release of white blood cells from bone marrow.

Question 10

Suppose you get a cut on your finger,and bacteria enter your skin through the cut.What would be the immediate response by your immune system?

A)Apoptosis of nearby body cells would occur.
B)Interferons would be released.
C)Natural killer cells would be activated.
D)The complement system would be activated.

Question 11

Mammals have Toll-like receptors (TLRs)that can recognize a kind of macromolecule that is absent from vertebrates but present in/on certain groups of pathogens,including viral

A)lipopolysaccharides.
B)double-stranded DNA.
C)double-stranded RNA.
D)glycoproteins.
E)phospholipids.

Question 12

Adaptive immunity depends on

A)traits common to groups of pathogens.
B)pathogen-specific recognition.
C)maternal provision of antibodies to offspring.
D)plants being exposed to new pathogens.
E)having exhausted all options for innate immunity responses.

Question 13

Innate immunity

A)is activated immediately upon infection.
B)depends on a newly infected animal's previous exposure to the same pathogen.
C)is based on recognition of antigens that are specific to different pathogens.
D)is found only in vertebrate animals.
E)utilizes highly specific antigen receptors on B cells.

Question 14

Infection by a bacterium that has elements on its surface that enhance its resistance to lysozyme will likely result in

A)destruction of the bacterium by natural killer cells.
B)successful reproduction of the bacterium and continued progression of the disease.
C)the infected individual's humoral immunity becoming the only route of infection response.
D)lymphocytes having an increased ability to attack the bacterium.

Question 15

An inflammation-causing signal released by mast cells at the site of an infection is (are)

A)interferons.
B)lymph.
C)histamine.
D)mucus.
E)antibodies.

Question 16

The cells and signaling molecules that initiate inflammatory responses are

A)the phagocytes and the histamines.
B)the dendritic cells and the interferons.
C)the mast cells and the histamines.
D)the lymphocytes and the interferons.

Question 17

Septic shock,a systemic response including high fever and low blood pressure,is a response to

A)certain bacterial infections.
B)specific forms of viruses.
C)the presence of natural killer cells.
D)a fever of > 103°F in adults.
E)increased production of neutrophils.

Question 18

An invertebrate,such as an insect,has innate immunity activity in its intestine that likely includes

A)complement.
B)lysozyme.
C)mucus.
D)neutrophils.
E)dendritic cells.

Question 19

In some insects,such as Drosophila,fungal cell wall elements can activate the protein Toll,which

A)acts as a receptor that,when activated,signals synthesis of antimicrobial peptides.
B)functions directly to attack the fungi presented to it.
C)produces antimicrobial peptides by interaction with chitin.
D)secretes special recognition signal molecules that identify specific pathogens.
E)causes some hemocytes to phagocytize the pathogens.

Question 20

Cave art by early humans recognized the existence of the major signs of inflammation.The most inclusive set of symptoms of inflammation that might appear in such early human art is

A)heat,pain,and redness.
B)pain and whitening of the surrounding tissue.
C)swelling and pain.
D)antibody-producing cells.
E)swelling,heat,redness,and pain.

Question 21

The number of major histocompatibility complex (MHC)protein combinations possible in a given population is enormous.However,an individual in that diverse population has a far more limited array of MHC molecules because

A)the MHC proteins are made from several different gene regions that are capable of rearranging in a number of ways.
B)MHC proteins from one individual can only be of class I or class II.
C)each of the MHC genes has a large number of alleles,but each individual only inherits two for each gene.
D)once a B cell has matured in the bone marrow,it is limited to two MHC response categories.
E)once a T cell has matured in the thymus,it can only respond to two MHC categories.

Question 22

Clonal selection is an explanation for how

A)a single type of stem cell can produce both red blood cells and white blood cells.
B)V,J,and C gene segments are rearranged.
C)an antigen can provoke production of high levels of specific antibodies.
D)HIV can disrupt the immune system.
E)macrophages can recognize specific T cells and B cells.

Question 23

Clonal selection implies that

A)antigens increase mitosis in specific lymphocytes.
B)only certain cells can produce interferon.
C)a B cell has multiple types of antigen receptors.
D)the body selects which antigens to which to respond.

Question 24

An epitope is

A)part of the interferons that penetrate foreign cells.
B)a protein protruding from the surface of B cells.
C)an antibody that is dissolved in blood plasma.
D)the part of an antigen that binds to an antigen receptor.

Question 25

Immunological memory accounts for

A)the human body's ability to distinguish self from nonself.
B)the observation that some strains of the pathogen that causes dengue fever cause worse disease than others.
C)the ability of a helper T cell to signal B cells via cytokines.
D)the ancient observation that someone who had recovered from the plague could safely care for those newly diseased.
E)the ability of the immune system to present antigen fragments in association with MHC antigens.

Question 26

A key part of the humoral immune response is

A)the attack of cytotoxic T cells on infected host cells.
B)the production of antibodies by plasma cells.
C)the attack of phagocytes on living pathogens.
D)the initiation of programmed cell death in infected host cells.

Question 27

Light chains of immunoglobulin (Ig)molecules C and V are made up of what regions?

A)one C region and one V region
B)three C regions and one V region
C)two C regions and two V regions
D)two C regions and one V region

Question 28

Antihistamine treatment reduces

A)blood vessel dilation.
B)phagocytosis of antigens.
C)MHC presentation by macrophages.
D)the secondary immune response.
E)clonal selection by antigens.

Question 29

Clonal selection of B cells activated by antigen exposure leads to production of

A)large numbers of neutrophils.
B)large quantities of the antigen initially recognized.
C)vast numbers of B cells with random antigen-recognition receptors.
D)long-lived red blood cells that can later secrete antibodies for the antigen.
E)short-lived plasma cells that secrete antibodies for the antigen.

Question 30

For the successful development of a vaccine to be used against a pathogen,it is necessary that

A)the surface antigens of the pathogen do not change.
B)a rearrangement of the B cell receptor antibodies takes place.
C)all of the surface antigens on the pathogen be identified.
D)the pathogen has only one epitope.
E)the MHC molecules are heterozygous.

Question 31

Antigens are

A)proteins found in the blood that cause foreign blood cells to clump.
B)foreign molecules that trigger an inflammatory response.
C)proteins that consist of two light and two heavy polypeptide chains.
D)foreign molecules that trigger the generation of antibodies.

Question 32

B cells have antigen receptors that bind to antigens that are either freely dissolved or present on the surface of invading/foreign cells.T cells have antigen receptors that

A)are active only in lymph nodes.
B)bind only to antigens present on the surface of the invading/foreign cells.
C)bind only to freely dissolved antigens in the plasma.
D)bind to antigen fragments presented on major histocompatibility complexes by host cells.
E)bind to antigens that are either freely dissolved or present on the surface of invading/foreign cells.

Question 33

The switch of a B cell from producing one class of antibody to another antibody class that is responsive to the same antigen is due to

A)mutation in the genes of that B cell,induced by exposure to the antigen.
B)the rearrangement of V region genes in that clone of responsive B cells.
C)a switch in the kind of antigen-presenting cell that is involved in the immune response.
D)a patient's reaction to the first kind of antibody made by the plasma cells.
E)the rearrangement of immunoglobulin heavy-chain C region DNA.

Question 34

Suppose there is a phagocytic cell in which the pH inside the lysosome is significantly higher than normal.What outcome regarding phagocytosis is most likely to occur?

A)Phagocytosis will be able to proceed normally.
B)Pathogens will able to be broken down but not released from the cell.
C)Pathogens will not be able to enter the cell.
D)Pathogens will be able to enter the cell but will not be able to be broken down.

Question 35

A newborn who is accidentally given a drug that destroys the thymus would most likely

A)lack class I MHC molecules on cell surfaces.
B)lack humoral immunity.
C)be unable to genetically rearrange antigen receptors.
D)be unable to produce mature T cells.
E)have a reduced number of B cells and be unable to form antibodies.

Question 36

Bacterial infection in a previously uninfected house cat would most quickly activate its

A)toll-like receptors.
B)memory cells.
C)plasma cells.
D)cytotoxic T cells.
E)humoral immune responses.

Question 37

What is the function of an antibody?

A)to inject toxins into living pathogens
B)to secrete cytokines that attract macrophages to infection sites
C)to bind to Toll-like receptors
D)to mark pathogenic cells for destruction

Question 38

The major histocompatibility complex (MHC)is important in a T cell's ability to

A)trigger an adaptive immune response.
B)recognize specific parasitic pathogens.
C)identify specific bacterial pathogens.
D)identify specific viruses.
E)trigger an innate immune response.

Question 39

The ability of one person to produce over a million different antibody molecules does not require over a million different genes;rather,this wide range of antibody production is due to

A)alternative splicing of exons after transcription.
B)increased rate of mutation in the RNA molecules.
C)rearrangements of randomly selected V and J coding fragments in DNA.
D)expression of different cytosolic proteins in the thymus cells.
E)crossing over between the light and heavy chains of each antibody molecule during meiosis I.

Question 40

Antibodies are made up of

A)one heavy chain and one light chain.
B)two heavy chains and two light chains.
C)three heavy chains and three light chains.
D)four heavy chains and four light chains.

Question 41

In which situation would helper T cells be activated?

A)when an antigen is displayed by a dendritic cell
B)when a cytotoxic T cell releases cytokines
C)when natural killer (NK)cells come in contact with a tumor cell
D)when B cells respond to T-independent antigens

Question 42

Which type of immunity is present only when a newborn infant is fed by nursing and ends when nursing ends?

A)innate immunity
B)passive immunity
C)cell-mediated immunity
D)adaptive immunity

Question 43

Arrange these components of the mammalian immune system as it first responds to a pathogen in the correct sequence.
I)Pathogen is destroyed.
II)Lymphocytes secrete antibodies.
III)Antigenic determinants from pathogen bind to antigen receptors on lymphocytes.
IV)Lymphocytes specific to antigenic determinants from pathogen become numerous.
V)Only memory cells remain.

A)I → III → II → IV → V
B)III → II → I → V → IV
C)II → I → IV → III → V
D)IV → II → III → I → V
E)III → IV → II → I → V

Question 44

Jazmin is a 44-year-old female who can produce antibodies against some bacterial pathogens but not against viral infections.Jazmin probably has a disorder in her

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

Question 45

Which of the following cells are involved in cell-mediated immunity and also respond to class I MHC molecule-antigen complexes?

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

Question 46

Normal immune responses can be described as polyclonal because

A)blood contains many different antibodies and antigens.
B)multiple immunoglobulins are produced from descendants of a single B cell.
C)diverse antibodies are produced for different epitopes of a specific antigen.
D)macrophages,T cells,and B cells all are involved in a normal immune response.

Question 47

Secondary immune responses upon a second exposure to a pathogen are due to the activation of

A)natural killer cells.
B)memory cells.
C)macrophages.
D)B cells.
E)T cells.

Question 48

Naturally acquired passive immunity results from the

A)injection of vaccine.
B)ingestion of interferon.
C)placental transfer of antibodies.
D)absorption of pathogens through mucous membranes.
E)injection of antibodies.

Question 49

A mutation in the gene for CD4 leads to the production of nonfunctioning CD4 proteins in the plasma membrane of a helper T cell.What role would the helper T cell be unable to perform?

A)response to T-independent antigens
B)lysing tumor cells
C)stimulating a cytotoxic T cell
D)interacting with a class I MHC-antigen complex
E)interacting with a class II MHC-antigen complex

Question 50

The receptors on T cells and B cells bind to

A)antibodies.
B)antigens.
C)natural killer cells.
D)double-stranded RNA.
E)immunoglobulins.

Question 51

The primary function of humoral immunity is to

A)defend against fungi and protozoa.
B)reject transplanted tissues.
C)protect the body against cells that become cancerous.
D)protect the body against extracellular pathogens.
E)defend against bacteria and viruses that have already infected cells.

Question 52

B cells that interact with helper T cells are stimulated to differentiate when

A)B cells produce antibodies.
B)B cells release cytokines.
C)helper T cells present the class II MHC molecule-antigen complex on their surface.
D)helper T cells differentiate into cytotoxic T cells.
E)helper T cells release cytokines.

Question 53

The cell-mediated immunity that destroys virally infected cells involves

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

Question 54

A cell type that interacts with both the humoral and cell-mediated immune pathways is a

A)plasma cell.
B)cytotoxic T cell.
C)natural killer cell.
D)helper T cell.

Question 55

In active immunity,but not passive immunity,there is

A)acquisition and activation of antibodies.
B)proliferation of lymphocytes in bone marrow.
C)the transfer of antibodies from the mother across the placenta.
D)the requirement for direct exposure to a living or simulated pathogen.
E)the requirement of secretion of cytokines from T cells.

Question 56

Select the pathway that would lead to the activation of cytotoxic T cells.

A)B cells contact antigen → helper T cell is activated → clonal selection occurs
B)body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface
C)self-tolerance of immune cells → B cells contact antigen → cytokines released
D)complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released
E)cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis

Question 57

Yearly vaccination of humans for influenza viruses is necessary because

A)of an increase in immunodeficiency diseases.
B)flu can generate anaphylactic shock.
C)surviving the flu one year exhausts the immune system to non-responsiveness the second year.
D)mutations of DNA in rapidly evolving generations of flu viruses result in altered surface proteins in infected host cells.
E)flu leads to autoimmune disorders.

Question 58

T cells of the immune system include

A)cytotoxic and helper cells.
B)plasma,antigen-presenting,and memory cells.
C)lymphocytes,macrophages,and dendritic cells.

Question 59

When antibodies bind antigens,they may clump together.Why does this occur?

A)because antibodies have at least two binding regions for antigens
B)because disulfide bridges form between the antigens
C)because bonds form between class I and class II MHC molecules
D)because the antibodies denature

Question 60

Among the last line of defenses against prolonged exposure to an extracellular pathogen is

A)lysozyme production.
B)phagocytosis by neutrophils.
C)antibody production by plasma cells.
D)histamine release by basophils.
E)conversion of helper T cells to memory helper T cells.

Question 61

A patient complaining of watery,itchy eyes and sneezing after being given a flower bouquet as a birthday gift should first be treated with

A)a vaccine.
B)complement.
C)antihistamines.
D)monoclonal antibodies.

Question 62

Activation of helper T cells by an antigen will directly activate

A)B cells only.
B)cytotoxic T cells only.
C)memory helper T cells only.
D)B cells and cytotoxic T cells only.
E)cytotoxic T cells and memory helper cells only.

Question 63

In the human disease known as lupus,there is an immune reaction against a patient's own DNA from broken or dying cells,which categorizes lupus as

A)an allergy.
B)an immunodeficiency.
C)an autoimmune disease.
D)an antigenic variation.
E)a cancer.

Question 64

An immune response to a tissue graft will differ from an immune response to a bacterium because

A)MHC molecules of the donor may stimulate rejection of the graft tissue,but bacteria lack MHC molecules.
B)the tissue graft,unlike the bacterium,is isolated from the circulation and will not enter into an immune response.
C)a response to the graft will involve B cells and a response to the bacterium will not.
D)a bacterium cannot escape the immune system by replicating inside normal body cells.
E)the graft will stimulate an autoimmune response in the recipient.

Question 65

Suppose a T cell had no access to the amino acid cysteine.What consequence would this have with regard to the immune response of the T cell?

A)Antibodies would not be produced.
B)Histamine would not be released.
C)Antigen receptors would not form properly.
D)CD4 would not bind to MHC II molecules.

Question 66

An individual who has been bitten by a poisonous snake that has a fast-acting toxin would likely benefit from

A)vaccination with a weakened form of the toxin.
B)injection of antibodies to the toxin.
C)injection of histamine.
D)injection of interferon.

Question 67

Which cell type is incorrectly matched with its function?

A)cytotoxic T cell-kills infected host cells
B)helper T cell-activates innate immune responses
C)plasma cell-produces antibodies
D)memory cell-gives rise to effector cells

Question 68

Preventing the appearance of the symptoms of an allergy attack would be the likely result of

A)reducing the ability of antibodies to attach to mast cells.
B)reducing the number of helper T cells in the body.
C)reducing the number of cytotoxic cells.
D)reducing the number of natural killer cells.

Question 69

Through the evolution of antigenic variation,pathogens are able to

A)change the epitopes they express to elude a secondary immune response.
B)change their genome to elude a secondary immune response.
C)change the types of RNAs they express to elude a secondary immune response.
D)change their size to elude a secondary immune response.

Question 70

The ability of some viruses to remain inactive (latent)for a period of time is exemplified by

A)influenza,a particular strain of which returns every 10-20 years.
B)herpes simplex viruses (oral or genital),whose reproduction is triggered by physiological or emotional stress in the host.
C)Kaposi's sarcoma,which causes a skin cancer in people with AIDS but rarely does so in those not infected by HIV.
D)the virus that causes a form of the common cold,which recurs in patients many times in their lives.

Question 71

In which of the following persons would the risk of developing a viral-induced cancer (such as Kaposi's sarcoma)be highest?

A)an adult with weakened barrier defenses
B)an adult with a weakened innate immune system
C)an adult with a weakened adaptive immune system

Question 72

Aaleyah has previously donated blood to her cousin Mohammed for a blood transfusion.However,a bone marrow transplant from Aaleyah to Mohammed may not be possible because

A)even though Aaleyah's blood type is a match to Mohammed's,her MHC proteins may not be a match.
B)a blood type match is less stringent than a match required for transplant because blood is more tolerant of change.
C)for each gene,there is only one blood allele but many tissue alleles.
D)Aaleyah's class II genes are not expressed in bone marrow.
E)Mohammed's immune response has been made inadequate before he receives the transplant.

Question 73

Suppose a B cell is unable to perform alternative splicing.What consequence will this have in regards to the immune response of the B cell?

A)The B cell will produce fewer cytokines.
B)The B cell will make a limited number of antigen receptors.
C)The B cell will not be able to engulf pathogenic bacteria.
D)The B cell will not be able to produce any antibodies at all.

Question 74

There is a mutation such that mast cells cannot produce and secrete histamine.Which of the following outcomes is most likely to happen if an injury to the skin occurs?

A)Macrophages will not be able to secrete cytokines.
B)Neutrophils will not be attracted to the injury site.
C)Neutrophils will not be able to phagocytose pathogens at the injury site.
D)Macrophages will not be able to phagocytose pathogens at the injury site.

Question 75

What is the main reason that HIV usually cannot be completely eliminated by the body's immune system?

A)The virus infects B cells.
B)The virus does not trigger an innate immune response.
C)The virus has a high mutation rate.
D)The virus is too small.

Question 76

Juan is a 5-year-old boy and recently recovered from the chickenpox.He returned to kindergarten and found out that his friend Tram had chickenpox too.Normally chickenpox is very infectious,but Juan did not acquire it again.Why was Juan protected from a second exposure to chickenpox?

A)because his immune system now has immunological memory
B)because his innate immune system was strengthened
C)because his inflammatory response was conditioned for chickenpox
D)because his immune system underwent antigenic variation

Question 77

A researcher suspects that a weakened immune response may be due to poor antigen presentation.Which experiment would best test this hypothesis?

A)Expose B cells to different antigens,and measure the proliferation rate.
B)Expose T cells to different antigens,and identify what is bound to the MHC molecules.
C)Expose natural killer cells to different antigens,and quantify the amount of chemicals released.

Question 78

There is a mutation in the gene for CD4 in a helper T cell such that it is transcribed and translated,but it cannot bind to class II MHC molecules.What effect will this have on the adaptive immune response?

A)Histamine would not be produced at all.
B)Cytotoxic T cells would not be as effective as normal.
C)Antibodies would not be produced as readily.
D)Lymphocytes would not differentiate as quickly.

Question 79

An example of a pathogen that undergoes rapid changes resulting in antigenic variation is

A)the influenza virus,which expresses alternative envelope proteins.
B)the strep bacteria,which can be communicated from patient to patient with high efficiency.
C)human papillomavirus,which can remain latent for several years.
D)the causative agent of the autoimmune disease known as rheumatoid arthritis.
E)multiple sclerosis,which attacks the myelinated cells of the nervous system.

Question 80

A patient who undergoes a high level of histamine release,dilation of blood vessels,and an acute drop in blood pressure is likely suffering from

A)an autoimmune disease.
B)a typical allergy that can be treated by antihistamines.
C)an organ transplant,such as a skin graft.
D)the effect of exhaustion on the immune system.
E)anaphylactic shock immediately following exposure to an allergen.