CH 12 MICRO

Antibodies do all the following except A) increase phagocytosis by opsonization. B) activate the complement cascade. C) activate killing by T cytotoxic cells. D) increase phagocytosis by agglutination of antigens. E) neutralize antigens to prevent binding to host cells.

C) activate killing by T cytotoxic cells.

Postexposure prophylaxis, a form of artificial passive immunity, is often given when a person is bitten by an animal that is suspected of having rabies, or if the rabies-status of the animal cannot be confirmed. What specifically, is being given to the patient in this type of treatment? A) effector B and T cells from a host who has developed an immune response to the rabies virus B) antigen-presenting cells which increase the rate at which the rabies antigens can be presented to T cells for activation C) antibodies harvested from a host who has developed an immune response to the rabies virus D) antigens from the rabies virus E) memory cells from a host who has developed an immune response to the rabies

C) antibodies harvested from a host who has developed an immune response to the rabies virus

T-independent antigens A)may be polysaccharides or proteins, and are not able to bind multiple B cell receptors on a given B cell. B) are able to bind multiple B cell receptors on a given B cell. C) are usually polysaccharides and able to bind multiple B cell receptors on a given B cell. D) are usually polysaccharides. E) are usually proteins.

C) are usually polysaccharides and able to bind multiple B cell receptors on a given B cell.

Which lymphocyte type is shown attacking the infected cell in the figure? A) B cell B) memory T cell C) cytotoxic T cell D) antigen-presenting cell E) helper T cell

C) cytotoxic T cell

The cellular branch of adaptive immunity A) is based on antibody production. B) is based on the activity of both T and B cells. C) is organized by T helper cells and carried out by T cytotoxic cells. D) is organized by T cytotoxic cells and carried out by T helper cells. E) does not involve a memory function.

C) is organized by T helper cells and carried out by T cytotoxic cells.

In contrast to a primary immune response, immunological memory A) generates higher antibody titers. B) provides a rapid reactivation of both cellular and humoral responses. C) provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen. D) generates antibodies with enhanced affinity for its antigen. E) provides a rapid reactivation of humoral responses only by generating higher antibody titers and antibodies with increased affinity for its antigen.

C) provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen.

Which number on the diagram is labeling the portion of the antibody that makes it specific for the antigen is binds to? A) 1 B) 2 C) 3 D) 4 E) 5

D) 4

How does adaptive immunity differ from innate immunity? A) Adaptive immunity generates immunological memory. B) Adaptive immunity is specific to each pathogen. C) Adaptive immunity generates immunological memory and its effects are immediate upon exposure to a pathogen. D) Adaptive immunity generates immunological memory and is specific to a pathogen. E) Adaptive immunity's effects are immediate upon exposure to a pathogen.

D) Adaptive immunity generates immunological memory and is specific to a pathogen.

Which stage of the humoral response is pictured? A) B cell activation by a T-dependent antigen B) isotype switching C) B cell differentiation D) B cell activation by a T-independent antigen E) B cell proliferation

D) B cell activation by a T-independent antigen

The most abundant antibody class in the body, found in all body fluids, is A) IgA. B) IgD. C) IgE. D) IgG. E) IgM.

D) IgG.

A newly-generated T cell can recognize MHCs and is not self-reactive. What is its fate? A) It will become part of an autoimmune attack in the body's tissues at some time in the future. B) It will undergo genetic shuffling to change its receptor to increase self-tolerance. C) It will migrate to the bone marrow for screening for the ability to make antibodies against self-antigens. D) It will migrate to the lymphoid tissues to await activation by its antigen. E) It is signaled for destruction via apoptosis.

D) It will migrate to the lymphoid tissues to await activation by its antigen.

Which statement is not true about MHC II? A) MHC II is present only on antigen-presenting cells. B) When bound to antigen, MHC II serves a key role in activation of the appropriate T cells. C) MHC II primarily displays extracellular antigens which have been phagocytized. D) MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells. E) MHC II interacts with the CD4 receptor on T helper cells.

D) MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.

Which T cell class is incorrectly matched with its description? A) TH2: stimulate B cells to make antibodies B) TH: identified by the CD4 proteins on the cell surface C) Treg: ensures that immune responses subside once a threat subsides D) TC: attack other T cells during self-tolerance screening E) TH1: stimulate TC cells

D) TC: attack other T cells during self-tolerance screening

By which means of acquiring immunity is likely to produce the longest lasting protection? A) passive B) natural C) artificial D) active E) Active, artificial, natural, and passive all provide equally long-lasting protection.

D) active

Advantages of isotype switching include A) ability to respond to multiple epitopes of the same antigen with the same B cell, expanded antibody response as different isotypes predominate in different areas of the body, and rapid response when a pathogen engages in antigen variation. B) ability to respond to multiple epitopes of the same antigen with the same B cell and rapid response when a pathogen engages in antigen variation. C) ability to respond to multiple epitopes of the same antigen with the same B cell. D) expanded antibody response as different isotypes predominate in different areas of the body. E) rapid response when a pathogen engages in antigen variation.

D) expanded antibody response as different isotypes predominate in different areas of the body.

Consider a genetic mutation which causes T helper cells to be unable to respond to stimulation by the cytokines which lead to TH2 differentiation. This mutation would cause a patient to be deficient in which activity? A) action of macrophage B) action of cytotoxic T cells C) decrease of the immune response once the pathogen is eliminated D) production of antibodies E) production of memory cells

D) production of antibodies

Which statement does not apply to haptens? A) Haptens are generally too small to be immunogenic on their own. B) Antibiotics such as penicillin are often haptens. C) Haptens must bind to a more complex molecule to stimulate an immune response. D) Haptens are also known as incomplete antigens. E) Haptens are any nonpathogenic substance, rather than a microorganism, which can stimulate an immune response.

E) Haptens are any nonpathogenic substance, rather than a microorganism, which can stimulate an immune response.

Generally, the first antibody class made upon a primary antigen exposure is A) IgA. B) IgD. C) IgE. D) IgG. E) IgM.

E) IgM.

How is the immune system able to recognize a limitless number of different antigens and epitopes? A) If a lymphocyte encounters an antigen it does not recognize, it immediately switches receptors until it finds one that is a match. B) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope AND the immune system produces a wide variety of lymphocytes. C) A genetic "memory" of the pathogens your parents encountered (and their parents and so on) is passed on to each generation, increasing the number of possible responses over time. D) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope. E) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors.

E) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors.

Cytotoxic T cells eliminate pathogens by A) releasing chemicals which are toxic to cellular pathogens. B) coordinating the activities of other immune cells. C) ingesting and digesting cellular pathogens. D) ingesting and digesting infected or cancerous cells. E) releasing chemicals which cause infected or cancerous cells to undergo

E) releasing chemicals which cause infected or cancerous cells to undergo

The branches of adaptive immunity are A) the antigen response and the memory response. B) the cellular response, the humoral response, and the memory response. C) the cellular response and the memory response. D) the humoral response and the memory response. E) the cellular response and the humoral response.

E) the cellular response and the humoral response.

A patient antibody titer which shows an increasing level of IgM but very little IgG would likely indicate that A) the patient has nearly recovered from the infection. B) the patient is having an allergic reaction. C) the patient is currently a nursing mother. D) the patient was vaccinated against this pathogen rather than having the infection. E) the patient is in the early stages of developing an immune response.

E) the patient is in the early stages of developing an immune response.

What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response? A) to release the cytokines needs for immune cell stimulation B) to combine with haptens so they can stimulate an immune response C) to communicate with lymphocytes and other white blood cells D) to release chemicals which destroy pathogens E) to recognize specific epitopes of an antigen

E) to recognize specific epitopes of an antigen

Each antibody molecule consists of A) a "heavy" protein chain. B) one light and one heavy protein chain. C) various combinations of light and heavy protein chains. D) a "light" protein chain. E) two light and two heavy protein chains.

E) two light and two heavy protein chains.

The antibody found in breastmilk and coating mucous membranes is A) IgA. B) IgD. C) IgE. D) IgG. E) IgM.

A) IgA.

What is the role of MHC I in the immune response? A) MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. B) MHC I is found on all body cells except red blood cells. C)MHC I is found only on antigen-presenting cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. D) MHC I is found only on antigen-presenting cells. E) MHC I presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.

A) MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.

Isotype switching occurs when A) a B cell changes which antibody class it is producing. B) an antibody changes which class it is. C) activated B cells differentiate into either plasma or memory cells. D) a B cell switches which epitope it recognizes. E) an antibody changes epitope it can recognize.

A) a B cell changes which antibody class it is producing.

Pregnant women are usually advised to be vaccinated against influenza to protect themselves and the baby after birth. The mother will acquire ________ immunity from the vaccine while the baby will acquire ________ immunity. A) artificial active; natural passive B) artificial active; artificial passive C) artificial active; artificial active D) natural active; natural passive E) artificial passive; artificial passive

A) artificial active; natural passive

All the following apply to T cells except A) coordinate the humoral response by making antibodies. B) reside in the lymphoid tissue. C) mature in the thymus. D) have the capacity to recognize virtually any type of antigen. E) originate in the bone marrow.

A) coordinate the humoral response by making antibodies.

A substance that may trigger an immune response, if presented in the right context is termed a(n) A) effector. B) antigen. C) cytokine. D) hapten. E) antibody

A) effector.

IgE antibody, which is associated with allergic responses A) encourages mast cells and basophils to release chemicals such as histamine and leukotrienes. B) is resistant to destruction by stomach acid. C) is usually found circulating in the bloodstream. D) is passed from mother to child through breastfeeding and may prevent the development of allergies in the child. E) can be found bound to B cells.

A) encourages mast cells and basophils to release chemicals such as histamine and leukotrienes.

All the following apply to B cells except A) play a critical role in both the cellular and humoral responses. B) reside in the lymphoid tissue. C) coordinate the humoral response by making antibodies. D) originate in the bone marrow. E) mature in the bone marrow.

A) play a critical role in both the cellular and humoral responses.

The graph shows A) primary antigen exposure. B) natural passive immunity. C) likely immune response upon exposure to a pathogen for which the patient has been vaccinated. D) immunological memory. E) secondary antigen exposure.

A) primary antigen exposure.

T/F switching of antibodies is beneficial because some pathogens are able to alter their antigens.

FALSE

T/F Allorecognition occurs when B and T cells are screened for self-tolerance.

FALSE

T/F T cell subclass differentiation allows T cell clones to recognize different epitopes of the same antigen.

FALSE

T/F Artificial immunity is characterized by short-lived protection immune protection because the patient is not making their own memory cells or antibodies.

FALSE

T/F Both the cellular and humoral branches of adaptive immunity have the goal of eliminating an identified antigen, but only the humoral branch develops a memory of the antigen so that future responses are faster.

FALSE

When "matching" a donated organ or tissue to a recipient, it is necessary that the ________ of the donor and the recipient be as similar as possible. A) T helper cells B) MHCs C) APCs D) blood type E) antibodies

B) MHCs

Which statement provides the best explanation of the need for self-tolerance screening of lymphocytes? A) It is necessary to have some lymphocytes with receptors that are self-tolerant to respond to intracellular infections by viruses. B) The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues. C) The process which generates the vast array of diverse antigen receptors is a highly-controlled process, so the generation of receptors which can bind to the body's own tissues is a rare occurrence due to a genetic mutation. D) Self-tolerance involves "self" lymphocytes which bind to and form a protective layer over all body tissues. E) Lymphocytes which would attack the body's own tissues are never generated.

B) The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues.

Which of the following is not required for T cell activation? A) co-stimulatory proteins B) antibody C) involvement of CD4 or CD8 D) bound antigen E) MHC I or II

B) antibody

The difference between T cell activation by normal antigens and T cell activation by superantigens is that superantigens A) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen and suppress cytokine release. B) are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen. C) suppress cytokine release. D) are not processed and presented by APCs. E) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.

B) are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.

Which is not a step in the process of B cell activation by a T-dependent antigen? A) binding of the antigen to the B cell receptor B) binding of the antigen to a T helper cell receptor C) processing and displaying the antigen with MHC II on the B cell D) release of cytokines by the T helper cell provide the second activation signal for the B cell E) interaction between co-stimulatory proteins on the B and T cells

B) binding of the antigen to a T helper cell receptor

The two-signal activation process for T cells includes A) the presence of antibodies AND binding between co-stimulatory proteins on the T cell and APC surfaces. B) interaction of the T-cell receptor with the MHC-antigen complex on the APC AND binding between co-stimulatory proteins on the T cell and APC surfaces. C) interaction of the T-cell receptor with the MHC-antigen complex on the APC AND the presence of a superantigen. D) the presence of a superantigen and the presence of appropriate antibodies. E) the presence of a superantigen AND binding between co-stimulatory proteins on the T cell and APC surfaces.

B) interaction of the T-cell receptor with the MHC-antigen complex on the APC AND binding between co-stimulatory proteins on the T cell and APC surfaces.

While not a hard-and-fast rule, molecules may be ranked from more immunogenic to less immunogenic. Which shows the correct ranking form more immunogenic to less immunogenic? A) haptens > lipids > polysaccharides > proteins B) proteins > polysaccharides > lipids > haptens C) polysaccharides > lipids > proteins > haptens D) haptens > proteins > lipids > polysaccharides E) Only haptens are less immunogenic; lipids, polysaccharides, and proteins have about equal immunogenicity.

B) proteins > polysaccharides > lipids > haptens

What is the role of memory cells? A) suppress the cellular response once the infection has passed B) remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen C) circulate in the body at elevated levels to maintain an active attack against any possible pathogen D) prevent an immune response against members of the normal microbiota E) provide immune protection specifically for central nervous system

B) remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen

The human immunodeficiency virus (HIV) selectively infects any cell which carries the CD42) surface glycoprotein. Which immune function will be impaired? A) stimulation of B and Tc cells but not of macrophage B) stimulation of macrophage, B and TC cells C) stimulation of B cells and antibody production D) stimulation of macrophage activity E) stimulation of Tc cells and destruction of virally-infected cells

B) stimulation of macrophage, B and TC cells

The amount of antibody present in the blood is termed the antibody ________. A) specificity B) titer C) affinity D) isotype E) effector

B) titer

The antibody class which is involved in fighting parasites is A) IgA. B) IgD. C) IgE. D) IgG. E) IgM.

C) IgE.

Which statement is not true about T cell subclass differentiation? A) Which specific T helper cell subclass that develops may impact the progression and outcome of an infectious disease. B) T cell subclass differentiation is caused by the release of cytokines that is influenced by the antigen's nature and the amount present. C) Regardless of which T helper cell subclass develops during an immune response, the humoral response is not impacted. D) Particular combinations of cytokines will favor the development of some T cell subclasses over others. E) Each subclass will include both effector and memory cells.

C) Regardless of which T helper cell subclass develops during an immune response, the humoral response is not impacted.

T/F A patient with a high antibody titer to a pathogen for which there is no vaccination indicates that this person is currently infected with the pathogen or was infected in the past.

TRUE

T/F An antigen may consist of multiple epitopes, each of which recognized by different lymphocytes.

TRUE

T/F Both the light and the heavy chains of an antibody are involved with epitope recognition and binding.

TRUE

T/F Graft-versus-host disease occurs when transplanted bone marrow gives rise to B and T cells that attack the recipient's tissues.

TRUE

T/F The humoral immune response can enhance phagocytosis by either direct interaction of antibodies with their antigen, or though antibOdy activation of the complement cascade.

TRUE