Deck 43: The Immune System

Question 1

The complement system is ________.

A) a set of proteins involved in innate but not acquired immunity
B) a group of proteins that includes interferons and interleukins
C) a group of proteins that act together in a cascade fashion
D) a set of proteins that act individually to attack and lyse microbes

Answer 1

C

Question 2

The cells and signaling molecules involved in the initial stages of the inflammatory response are ________.

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

Answer 2

C

Question 3

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

A) interferons produced by immune cells
B) the secretion of complement proteins
C) the release of slightly alkaline secretions
D) the secretion of lysozyme onto their surfaces

Answer 3

D

Question 4

Innate immunity ________.

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

Question 5

Inflammatory responses typically include ________.

A) increased activity of phagocytes in an inflamed area
B) reduced permeability of blood vessels to conserve plasma
C) release of substances to decrease the blood supply to an inflamed area
D) inhibiting the release of white blood cells from bone marrow

Question 6

A strain of fruit fly lacks the ability to produce Dicer-2 protein. You might expect this strain to be more susceptible to ________ infections.

A) viral
B) bacterial
C) fungal
D) protozoan

Question 7

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

A) I and III
B) II and IV
C) I and IV
D) I, II, and III

Question 8

Bacteria entering the body through a small cut in the skin ________.

A) inactivate the erythrocytes
B) stimulate apoptosis of nearby body cells
C) stimulate release of interferons
D) activate a group of proteins called complement

Question 9

________ are receptor molecules on mammalian cells that recognize macromolecules that are present in or on certain groups of pathogens.

A) Cytokines
B) Toll-like receptors
C) Interferons
D) Complement proteins

Question 10

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) increased production of neutrophils

Question 11

Clonal selection and differentiation of B cells activated by antigen exposure leads to the production of ________.

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

Question 12

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

A) lack innate immunity
B) be unable to genetically rearrange antigen receptors
C) be unable to differentiate and mature T cells
D) have a reduced number of B cells and be unable to form antibodies

Question 13

You and a friend were in line for a movie when you noticed the woman in front of you sneezing and coughing. Both of you were equally exposed to the woman's virus, but over the next few days, only your friend acquired flu-like symptoms and was ill for almost a week before recovering. Which one of the following is a logical explanation for this?

A) Your friend had antibodies to that virus.
B) You had an immunological memory of that virus.
C) Your friend had an autoimmune disorder.
D) Your friend had allergies.

Question 14

Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by a(n)________.

A) RNA polymerase
B) reverse transcriptase
C) telomerase
D) recombinase

Question 15

A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. What response is occurring?

A) inflammatory response
B) lytic response
C) adaptive immune response
D) autoimmune response

Question 16

________ are cells of the mammalian innate immune response that help destroy tumors.

A) Cytotoxic T cells
B) Natural killer cells
C) Macrophages
D) B cells

Question 17

Mucus occurs in both the respiratory and digestive tracts. What is its main immunological function?

A) sweeping away debris
B) physically trapping of pathogens
C) destruction of pathogens because it is acidic
D) increasing oxygen absorption

Question 18

Use the graphs to answer the following question.
Mutant fruit flies that make only one antimicrobial peptide were tested for survival after infection with Neurospora crassa fungi or with Micrococcus luteus bacteria.


The results shown in the graphs support the hypothesis that ________.

A) adding the defensin gene to such mutants protects them from death by bacterial infection
B) adding the drosomycin gene to such mutants protects them from death by bacterial infection
C) wild-type flies with the full set of genes for antimicrobial peptides are highly susceptible to both fungal and bacterial pathogens
D) the presence of any single antimicrobial peptide protects against both fungal and bacterial pathogens

Question 19

Acidity in human sweat is an example of ________.

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

Question 20

Clonal selection is an explanation for how ________.

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

Question 21

B cells interacting with helper T cells are stimulated to differentiate when ________.

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

Question 22

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) plasma cell
B) thyroid cell
C) memory cell
D) macrophage

Question 23

________ is a characteristic of adaptive immunity but not innate immunity.

A) Memory
B) Inflammation
C) Interferons
D) Lysozyme

Question 24

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.

A) only I and III
B) only II and IV
C) only I, II, and IV
D) only II, III, and IV

Question 25

Use the following information to answer the question(s) below.
An otherwise healthy student in your class was infected with EBV (the virus that causes infectious mononucleosis) when she was a child, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. When she is exposed to EBV again later in life, she does not get sick or have any symptoms of mononucleosis.
Which of the following statements explains why your class mate does not exhibit symptoms of EBV infection?

A) She was likely infected with a weaker strain of EBV during her second exposure.
B) Complement proteins effectively controlled the EBV during the second infection.
C) Memory T cells quickly recognized the virus upon the second exposure and destroyed the virally infected cells.
D) Her innate immune response was better at recognizing the EBV antigen during the second infection.

Question 26

Immunological memory accounts for ________.

A) the human body's ability to distinguish self from non-self
B) the observation that some strains of the pathogen that causes dengue fever cause more severe 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

Question 27

How is a viral antigen, like EBV, recognized by T cells?

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

Question 28

Which of the following are similarities between B cells and T cells?
I)They both recognize antigen using immunoglobulin receptors.
II)Both B cells and T cells undergo clonal selection after encountering an antigen.
III)B cells and T cells both maintain an immunological memory of previously encountered antigens.

A) only III
B) only II
C) both II and III
D) both I and II

Question 29

Which of the following statements about epitopes are correct?
I)B cell receptors bind to epitopes.
II)T cell receptors bind to epitopes.
III)There can be 10 or more different epitopes on each antigen.
IV)There is a one-to-one correspondence between antigen and epitope.

A) only I and III
B) only II and IV
C) only I, II, and III
D) only II, III, and IV

Question 30

A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to ________.

A) respond to circulating viral antigens
B) lyse tumor cells
C) stimulate a cytotoxic T cell
D) interact with a class II MHC-antigen complex

Question 31

Which of the following proteins can be classified as immunoglobulins?
I)T cell receptors
II)B cell receptors
III)Antigens

A) only I
B) only II
C) both II and III
D) both I and II

Question 32

CD4 and CD8 are ________.

A) proteins secreted by antigen-presenting cells
B) receptors present on the surface of natural killer cells
C) molecules present on the surface of T cells where they interact with major histocompatibility (MHC) molecules
D) molecules on the surface of antigen-presenting cells where they enhance B cell activity

Question 33

What major advantage is conveyed by having a system of adaptive immunity?

A) It enables a rapid defense against an antigen that has been previously encountered.
B) It enables an animal to counter most pathogens almost instantly the first time they are encountered.
C) It results in effector cells with specificity for a large number of antigens.
D) It allows for the destruction of antibodies.

Question 34

T cells of the immune system include ________.

A) CD4, CD8, and plasma cells
B) cytotoxic and helper cells
C) plasma, antigen-presenting, and memory cells
D) lymphocytes, macrophages, and dendritic cells

Question 35

Vaccination offers protection against future exposure to pathogens because it ________.

A) stimulates the complement system
B) triggers clonal expansion of lymphocytes
C) promotes inflammation
D) enhances the activity of macrophages

Question 36

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

A) only I and III
B) only I and II
C) only II and III
D) I, II, and III

Question 37

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

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

Question 38

What type of immunity is associated with breast feeding?

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

Question 39

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

A) B cell 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) complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released
D) cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis

Question 40

An immunoglobulin (Ig) molecule, of any class, with regions symbolized as C or V, H or L, has a light chain made up of ________.

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

Question 41

Phagocytosis of microbes by macrophages is enhanced by ________.
I)the binding of antibodies to the surface of microbes
II)antibody-mediated opsonization of microbes
III)the release of cytokines by activated B cells

A) only I and II
B) only II and III
C) only I and III
D) I, II, and, III

Question 42

Which of the following should be the same in identical twins?

A) the set of antibodies produced
B) the set of major histocompatibility (MHC) molecules produced
C) the set of T cell antigen receptors produced
D) the susceptibility to a particular virus

Question 43

Which of the following components of the immune system destroys bacteria by punching holes in the wall of the bacteria?

A) complement protein
B) macrophages
C) plasma cells
D) major histocompatibility complex proteins

Question 44

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 interleukin-1
D) injection of interferon

Question 45

When antibodies bind antigens, the clumping of antigens results from ________.

A) the antibody having at least two binding regions
B) disulfide bridges between the antigens
C) bonds between class I and class II MHC molecules
D) denaturation of the antibodies

Question 46

A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin, Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because ________.

A) even though Jane's blood type is a match to Bob's, her major histocompatibility (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) Jane's MHC class II genes are not expressed in bone marrow

Question 47

A patient who has a high level of mast cell activity, dilation of blood vessels, and acute drop in blood pressure is likely suffering from ________.

A) an autoimmune disease
B) a typical skin allergy (contact dermatitis) that can be treated by antihistamines
C) an organ transplant, such as a skin graft
D) anaphylactic shock immediately following exposure to an allergen

Question 48

The number of major histocompatibility (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

Question 49

Jenner's successful use of cowpox virus as a vaccine against the smallpox virus was due to the fact that ________.

A) the immune system responds nonspecifically to antigens
B) the cowpox virus made antibodies in response to the presence of smallpox
C) there are some epitopes (antigenic determinants) common to both pox viruses
D) cowpox and smallpox are caused by the same virus

Question 50

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

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

Question 51

Yearly vaccination of humans for influenza viruses is necessary because ________.

A) of an increase in immunodeficiency diseases
B) the flu can generate anaphylactic shock
C) surviving the flu one year exhausts the immune system to nonresponsiveness the second year
D) rapid mutation in flu viruses alters the surface proteins in infected host cells

Question 52

Which of the following would help a virus avoid triggering an effective adaptive immune response?
I)having frequent mutations in genes for surface proteins
II)building the viral shell from host proteins
III)producing proteins very similar to those of other viruses
IV)infecting and killing helper T cells

A) only I and III
B) only I, II, and IV
C) only I, II, and III
D) only II, III, and IV

Question 53

Which of the following is crucial to activation of the adaptive immune response?

A) memory cells
B) presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface
C) activation of complement proteins
D) phagocytosis of antibody-antigen complex by macrophages in the blood

Question 54

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 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 55

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) sterile pollen
C) antihistamines
D) monoclonal antibodies

Question 56

Which of the following is the best definition of autoimmune disease?

A) a condition in which B and T cells trigger anaphylactic shock in response to an antigen
B) a condition in which the adaptive immune system fails to recognize the second infection by the same antigen
C) a condition in which self molecules are treated as nonself (loss of self-tolerance)
D) a condition in which the immune system creates random antibodies without being triggered by a specific antigen

Question 57

Which of the following components of the immune system destroys cancerous cells by punching holes in plasma membranes and triggering apoptosis?

A) toll-like proteins
B) macrophages
C) plasma cells
D) cytotoxic T cells

Question 58

Naturally acquired passive immunity can result from the ________.

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

Question 59

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) all of the surface antigens on the pathogen be identified
C) the pathogen has only one epitope
D) the major histocompatibility (MHC) molecules are heterozygous

Question 60

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 bacterium cannot escape the immune system by replicating inside normal body cells
D) the graft will stimulate an autoimmune response in the recipient

Question 61

Vaccination increases the number of

A) different receptors that recognize a pathogen.
B) lymphocytes with receptors that can bind to the pathogen.
C) epitopes that the immune system can recognize.
D) MHC molecules that can present an antigen.

Question 62

In a humoral or antibody-mediated immune response, specific B cells are stimulated by helper T cells to transform into plasma cells that secrete antibodies. What would be an important feature added to the plasma cells during this transition process that allows them to better perform their function?

A) duplication of specific gene sequences for the appropriate antibody
B) increased rough endoplasmic reticulum for greater antibody production
C) duplication of lysosomes in order to store the antibodies before transport
D) increased antigen presentation on the surface of the plasma cells

Question 63

Which of the following statements is not true?

A) An antibody has more than one antigen-binding site.
B) A lymphocyte has receptors for multiple different antigens.
C) An antigen can have different epitopes.
D) A liver or muscle cell makes one class of MHC molecule.

Question 64

An epitope associates with which part of an antigen receptor or antibody?

A) the tail
B) the heavy-chain constant regions only
C) variable regions of a heavy chain and light chain combined
D) the light-chain constant regions only

Question 65

Which of the following should be the same in identical twins?

A) the set of antibodies produced
B) the set of MHC molecules produced
C) the set of T cell antigen receptors produced
D) the set of immune cells eliminated as self-reactive

Question 66

Which of the following would not help a virus avoid triggering an adaptive immune response?

A) having frequent mutations in genes for surface proteins
B) infecting cells that produce very few MHC molecules
C) producing proteins very similar to those of other viruses
D) infecting and killing helper T cells

Question 67

Which statement best describes the difference between responses of effector B cells (plasma cells) and those of cytotoxic T cells?

A) B cells confer active immunity; cytotoxic T cells confer passive immunity.
B) B cells respond the first time a pathogen is present; cytotoxic T cells respond subsequent times.
C) B cells secrete antibodies against a pathogen; cytotoxic T cells kill pathogen-infected host cells.
D) B cells carry out the cell-mediated response; cytotoxic T cells carry out the humoral response.

Question 68

If a person is prone to allergies, what treatment could redirect their immune response to help prevent future allergic reactions?

A) stimulating activated B cells to switch antibody production from class IgE to class IgM
B) blocking the antigen recognition sites of IgM antibodies
C) reducing the number of helper T cells in the body
D) reducing the number of cytotoxic cells

Question 69

Which of these is not part of insect immunity?

A) enzyme activation of pathogen-killing chemicals
B) activation of natural killer cells
C) phagocytosis by hemocytes
D) production of antimicrobial peptides