CH 15 SB

Mature T cells express ______.

CD4 coreceptors CD8 coreceptors

Either ______________ or _____________ coreceptors are expressed on mature T cells.

CD4 or CD8

Which of the following would NOT be recognized by the immune system as foreign antigens?

Cells or substances from your own body

Cytotoxic T cells (with CD8 receptors) recognize antigen presented with MHC class ___ molecules.

1

How many different types of antigen specific receptors can be found on the surface of a given lymphocyte?

1

A molecule must have a molecular weight of _______ to elicit even a weak immune response.

1,000

Molecules less than _____________ MW are seldom good antigens since a substance must be large enough to attract the attention of immune system cells.

1,000

Naive T helper cells upon encountering antigen and MHC differentiate into TH ____ or TH _____ cells depending on the cytokine environment.

1,2

Match each antibody class with its biological function.

1. IgG matches Long term immunity, opsonization, neutralizes toxins 2.IgA matches Secretory antibody 3. IgM matches First antibody produced in response to antigen 4. IgD matches Choice, Serves as the B cell receptor Serves as the B cell receptor 5. IgE matches Allergies; worm infections

IgM has ________ antigen binding sites.

10

Helper T cells (with CD4 receptors) recognize antigen presented with MHC class ___ molecules.

2

An immunoglobulin molecule is made of _____ protein chains, which are ____ heavy chains and _____ light chains. (Use numbers)

4,2,2

How many protein chains are used to produce an immunoglobulin molecule?

4; two heavy chains and two light chains

Which of the following are the main antigen-presenting cells?

Dendritic cells B cells Macrophages

HIV infects T helper cells and severely reduces their number. Which of the following do you expect as a result of this?

A reduced ability of B cells to be activated A reduced ability of cytotoxic T cells to be activated

In most specific immune responses, antigen must be processed and presented by which of the following?

APCs

Which of the following is NOT a function of IgG?

Acting as a secretory antibody

_______________ is the aggregation formed by antibodies binding cellular antigens or large particles.

Agglutination

The presence of IgE on mast cells and basophils can lead to some destructive responses, including ______.

Allergies Asthma Anaphylaxis

T-cell dependent antigens, which are usually protein based, require recognition steps between the following cells and substances.

Antigen Lymphocytes Antigen presenting cells

Which antibody fragment is the effector portion of the molecule and binds to membranes of many different cells?

Fc

________ is the fragment of antibodies that serves as the effector portion of the molecule as it binds to the membranes of many different cells.

Fc

_____________ is the ability of a substance to elicit a specific immune response.

Antigenicity

T helper 2 cells stimulate which of the following cell types?

B lymphocytes

Antigens can be presented to T cells by B cells, ______________ cells and ______________.

Blank 1: dendritic Blank 2: macrophages

CD4 receptors are found on T ____________ cells and CD8 receptors are found on T __________ cells.

Blank 1: helper Blank 2: cytotoxic

B cells recognize antigen via ______________ receptors.

Blank 1: immunoglobulin, antibody, or ig

T helper cells activate B cells by releasing _____________and B cell _____________ factors.

Blank 1: interleukins, cytokines, or lymphokines Blank 2: growth

The three main antigen presenting cells are ___________ , as well as _____________ and B cells.

Blank 1: macrophages Blank 2: dendritic

Due to ______ during lymphocyte development, there is a huge diversity of possible lymphocytes each with distinct antigen receptors.

gene rearrangement

Enzymes secreted by cytotoxic T cells that damage proteins of target cells are called _______.

granzymes

____________ are enzymes released by T cytotoxic cells that are used to kill its target cell.

granzymes

A ___________ is an incomplete or partial antigen and must be attached to a carrier to elicit an immune response.

hapten

A molecule that cannot stimulate a full immune response without being attached to a larger protein molecule called a carrier is known as a(n) ________.

hapten

Antigen presented by MHC II class molecules on the surface of antigen presenting cells activates T _________ cells.

helper

T ____________ cells activate macrophages, resulting in an increased ability to induce inflammation.

helper

The CD4 coreceptor is expressed on T ___________ cells.

helper

The status of collective acquired immunity in a population that reduces the likelihood that nonimmune individuals will contract and spread infection is known as _____ immunity.

herd

__________ immunity is the collective protective immunity exhibited by a population which confers indirect protection to nonimmune members.

herd

Due to the property of ____ __________, nonvaccinated individuals are indirectly protected against a pathogen as a result of the collective immunity of vaccinated persons.

herd immunity

The principle that states that when there is a large number of individuals in a population that are immune to a pathogen, it is less likely that an non-immunized member of the population will encounter the pathogen is called ___________ ______________

herd immunity

________ is the principle that when there is a large number of individuals in a population that are immune to a pathogen, it is less likely that an non-immunized member of the population will encounter the pathogen.

herd immunity

The antigen binding sites on an antibody molecule are ______.

highly variable

Which of the following are principal activities of antibodies with respect to their specific antigens?

immobilize neutralize unite with (bind) call attention to

Any clinical process that produces immunity in an individual is called a(n) ________.

immunization

_____________ is any clinical procedure that produces either passive or active immunity in a subject.

immunization

The ability of the body to react to a myriad of foreign substances is termed ________.

immunocompetence

______________ is the ability of the body to react to a myriad of foreign substances.

immunocompetence

A type of antigen that is certain to induce a specific immune response when introduced into the body is called a(n) ___________

immunogen

The class of proteins to which antibodies belong are ________.

immunoglobulins

Preventing or treating infectious diseases by administering substances such as premade antibodies that produce artificial immunity is called ________.

immunotherapy

____________ is the medical procedure that may involve the transfer of premade antibodies to protect the individual.

immunotherapy

Due to herd immunity, nonvaccinated individuals are ______ protected from disease by the collective immunity of the immunized members of a population.

indirectly

B cells are activated by chemical signals called ______ produced by macrophages and T cells.

interleukins

With respect to B cell activation, T cells give off signals in the form of ______.

interleukins B cell growth factors

Immunoglobulins exist as structural and functional classes called ______.

isotypes

The different structural and functional classes of antibodies (immunoglobulins) are called _______________

isotypes

A ____________ or _____________ vaccine is one in which the entire pathogen is given but it has been treated in such a way that it can no longer multiply.

killed or inactivated

Antigen-presenting cells that both process and present antigenic determinants on their surfaces include B-cells, ___________ and dendritic cells.

macrophages

Chemical signals produced by ____________ and T cells called interleukins can activate B cells.

macrophages

One set of genes that codes for human cell receptors and plays a role in recognition of self by the immune system is the ___________ _________________ _____________(MHC).

major histocompatibility complex

Some specific immune cells can differentiate into ___________ cells, which persist long after a pathogen has been cleared and can reactivate during re-infection.

memory

The ______ response to previously seen antigens is the basis for the success of vaccinations.

memory

The basis of immunization is using antigen to produce immunologic ______________ to that antigen.

memory

___________ T or B cells remain for long periods to be ready to respond to the same antigen encountered at a later time.

memory

These cells remain in circulation for long periods of time and are ready to respond to a specific antigen should it be encountered again.

memory cells

Which of the following is a cell type that remains in the body long after a pathogen has been cleared, and can quickly respond if the body ever re-encounters the same pathogen?

memory cells

IgA circulates in the blood as a(n) ________.

monomer

In the blood, IgA circulates in the ______ form.

monomer

A potential problem with the use of live attenuated viruses is that the bacteria or virus can ____________ back to a virulent strain.

mutate

Any immunity that is acquired during the normal biological experiences of an individual, such as infection or through breast feeding is known as ________ immunity.

natural

_____________ immunity is acquired from infection or through breastfeeding from the mother; this immunity is acquired through normal life experiences.

natural

After recovery from an infectious disease, the resistance to reinfection is called ________ immunity.

natural active

Recovery from infectious disease results in ________________ _____________ immunity.

natural active

Which cells are usually the first cells to attack cancer cells and virus infected cells since they can act quickly and are not antigen specific?

natural killer

Which of the following lymphocytes is not antigen specific?

natural killer

________ ____________ cells are probably the first cells to attack cancer cells and virus-infected cells since they can act quickly and are not antigen specific.

natural killer

______________ _______________ cells are a type of lymphocyte with many similarities to T cells but the big difference is that they are NOT antigen specific.

natural killer

Which type of T cell is stimulated by both self and nonself lipids?

natural killer t cells

In ______________ reactions, antibodies bind to cells, viruses, or toxins thus blocking their ability to interact with host receptors.

neutralization

The binding of antibodies to cells, viruses, or toxins that results in the blocking of their ability to interact with host receptors is called ________.

neutralization

T-cell dependent antigens do NOT require recognition steps between which of the following cells or substances?

neutrophils

Cells and complex molecules usually have ______.

numerous antigenic epitopes

Each lymphocyte is genetically programmed to express ______ type(s) of antigen specific receptor(s).

one

The coating of nonself molecules with antibodies to increase their rate of phagocytosis is called .

opsonization

______ enhances phagocyte recognition by coating the invader with antibodies so that they will be more readily recognized by phagocytes.

opsonization

IgG has numerous functions, including ______.

opsonization crossing the placenta complement fixation toxin neutralization

Which of the following is not a common route of vaccine administration?

orally

Specific resistance that is acquired indirectly by donation of preformed immune substances (antibodies) produced in the body of another individual is called artificial ________ immunity.

passive

________________ immunity is the acquisition of premade antibodies either from the mother or via injection of immune serum.

passive

IgM is a __________ and thus has 10 antigen binding sites.

pentamer

Upon antigen activation, CD8 T cells release ______________ which are proteins that punch holes in the membranes of target cells.

perforins

________ are proteins released by activated cytotoxic T cells that punch holes in the membranes of target cells.

perforins

Which is NOT a B cell outcome following activation signals from a T cell?

phagocytosis

Upon antigen encounter, B lymphocytes differentiate into antibody producing cells called ____________ cells and memory cells that can quickly react with the same antigen in a subsequent encounter.

plasma

________ are differentiated B cells that produce and secrete large amounts of antibodies.

plasma

Antiserum from human blood contains ______________ antibodies arising from a wide variety of B-cell clones.

polyclonal

______ antibodies, produced by a wide variety of B-cell clones, are found in antiserum extracted from human blood.

polyclonal

_________________ antibodies, produced by a wide variety of B-cell clones, are found in antiserum extracted from human blood.

polyclonal

For small, free antigen molecules, such as proteins, the process of _____________ increases the speed of phagocytosis.

precipitation

The process that enhances phagocytosis of antigens much smaller than a cell, such as proteins, is ______.

precipitation

An antigen _______ cell is a cell that ingests and degrades an antigen and subsequently places the antigenic determinant molecules on its surface for recognition by CD4 T lymphocytes.

presenting

The __________ immune response is the initial antibody response upon encountering antigen.

primary

The first response of the immune system when exposed to an antigen is called a ________ immune response.

primary

During lymphocyte development, there is a huge diversity of possible lymphocytes, each with distinct antigen-specific receptors, that results from extensive _________________ of the gene fragments that code for T and B cells.

rearrangement

A given host cell can express several different surface molecules called ________, each of which has a role in detection, recognition, and cell communication.

receptors

An APC and a T cell form a complex between their ________ that triggers T cell activation.

receptors

During T cell activation, the APC and the T cell form a complex between their _______ that triggers T cell activation.

receptors

Microbes enter the human body most frequently through the ________ and ________ mucosa.

respiratory and gastrointestinal

Microbes enter the body most frequently through the ______________ tract or the ____ tract.

respiratory, GI

The ______ immune response is advantageous because it is faster and more vigorous at clearing antigen.

secondary

The __________ lymphoid tissues are continuously resupplied with B and T cells.

secondary

The _____________ response, also called the anamnestic response, is the specific immune response generated upon subsequent exposure to a previously seen antigen and it is directed by memory cells.

secondary

The advantage of a(n) ____________ immune response is that it is faster and more vigorous at clearing antigen than the primary immune response.

secondary

The anamnestic response is also called a ________ immune response.

secondary

The rapid rise in antibody titer following a repeat exposure to an antigen that has been recognized from a previous exposure is called a(n) ________ immune response.

secondary

According to the clonal _________ theory, lymphocyte specificity is genetically preprogrammed and exists before antigen has ever been encountered.

selection

The specific immune response is highly ___________ which means that a given antibody, B cell receptor, or T cell receptor only recognizes a specific antigen.

selective

During generation of receptor diversity, any lymphocytes that develop a specificity for ______ molecules could be harmful and are thus eliminated.

self

During the generation of lymphocyte receptor diversity, any cells that develop a specificity for ________ MHC molecules are eliminated.

self

MHC class I proteins allow for the recognition of ________ molecules.

self

The two features that characterize the specific immune response are ________________and _____________.

specificity and memory

Which of the following is NOT a feature that characterizes specific immunity:

speed

Secretory IgA is NOT found in which of the following fluids?

stomach acid

Bacterial proteins that are potent stimulators of T cells and can trigger massive release of cytokines leading to widespread cell death are called ___________

superantigens

Fairly large antigens which can actually induce problems by spanning both the MHC-II and T cell receptors (TCR) are called ________________.

superantigens

______, such as some bacterial toxins, are potent stimulators of T cells and are responsible for diseases such as toxic shock.

superantigens

____________ are potent stimulators of T cell responses and can result in overwhelming release of cytokines and cell death.

superantigens

The overall structure of an antibody is a(n) ______ shape.

symmetrical Y shape

Which cell types are needed to activate B cells in the absence of B cells activating independently?

t helper cells

After antigen stimulation, B cells produce antibodies to ______ antigens.

target inactivate neutralize

Specific immunity is highly selective which means that antibodies produced to a specific foreign protein antigen on a virus only recognize ______.

that specific antigen

Which is NOT a characteristic of the structure of an antibody?

Four different polypeptide chains

___________ is the antibody class that mediates anaphylaxis, asthma, and certain allergies.

IgE

At the beginning of an immune response most antibodies are IgM but as the response progresses you see production switch predominantly to which class of antibodies?

IgG

Which of the following is the most prevalent antibody in circulation and tissue fluids?

IgG

_____________________ is the most prevalent antibody in circulation and tissue fluids.

IgG

Early in the primary immune response, most antibodies are of which class?

IgM

Which is the first type of antibody produced by the body following exposure (first encounter) to a specific antigen?

IgM

_________ is the first class of antibody produced by the body in the primary response, that is upon first encounter with antigen.

IgM

_______________ is the class of antibodies that comprise the majority of antibodies produced early in the primary immune response.

IgM

What type of receptors do B cells utilize to recognize their specific antigen?

Immunoglobulin

________ are a class of glycoproteins that serve as the antigen-specific receptors on B cells.

Immunoglobulins

___________________ are the chemical class of proteins to which antibodies belong.

Immunoglobulins

Which of the following is NOT a characteristic of superantigens?

Inhibit cytokine release

The great majority of vaccines are administered by the following routes.

Intradermal injection Subcutaneous injection Intramuscular injection

A(n) _______________ exposes a person to a specific antigen preparation in order to trigger a protective specific immune response without the person suffering any effects associated with the pathogen.

vaccination

Exposing a person to the antigenic components of a microbe without its pathogenic effects for the purpose of inducing a future protective response is called ________.

vaccination

Host cell protein receptors involved in immune reactions recognize self proteins such as ________ molecules.

MHC

What is the name for molecules that, following antigen processing, bind the antigen fragment and display it on the surface of the cell?

MHC

What is the set of genes that encodes human cell receptors that play a role in recognition of self by the immune system called?

MHC

Which type of protein must be complexed with peptide to activate CD8 T cells?

MHC class I protein

Which type of protein must be complexed with peptide to activate CD4 T cells?

MHC class II proteins

MHC class II molecules are found on which of the following host cells?

Macrophages Dendritic cells B lymphocytes

Which of the following cell types are NOT stimulated by T helper 2 cells?

Monocytes Erythrocytes Cytotoxic T cells T helper 1 cells Dendritic cells

Biological functions associated with one or more of the different classes of antibodies include ______.

Neutralization Complement fixation Opsonization

Molecules shared by many types of microbes that stimulate a nonspecific response are called ______________

PAMPs

_______ are molecules that are shared by many types of microbes and capable of eliciting a nonspecific response.

PAMPs

Which of the following describes a form of active immunity?

vaccination

When considering pathogenic microbes, ______.

there are many that lack a vaccine

Which is the main function of IgD?

Serves as a B cell antigen receptor

The use of _________ has greatly reduced the prevalence and impact of many deadly infectious diseases.

vaccines

Which of the following has greatly reduced the prevalence and impact of many deadly infectious diseases?

vaccines

Clusters of differentiation (CD) receptors are molecules on the surfaces of ___ cells that act as receptors and may also be involved in cell adhesion and communication.

T

Cytotoxicity is the ability for this type of lymphocyte to kill specific target cells.

T

__ cells are responsible for cell-mediated immunity.

T

____ cells are the "mediators" of cell-mediated immunity.

T

Which immune system cells carry clusters of differentiation (CD) receptors?

T cells

Antigen presented by MHC class II on the surface of an APC can activate what cell type?

T helper

__________ ________ cells are involved in activating macrophages.

T helper

CD4 T cells can differentiate into which cell types when stimulated by antigen displayed on MHC?

T helper 1 T helper 2

It is believed that the secretion of interleukin-4 by APCs triggers the differentiation of T cells into which cell type?

T helper 2 cells

The CD4 coreceptor is found on the surface of which cell type?

T helper cells

Which of the following cell types does not express MHC class II molecules on its surface?

T lymphocytes

Which components are expressed on Natural Killer T cells?

T-cell receptors Natural Killer (NK) cell markers

The presence of IL4 directs the differentiation of T helper cells to ______ cells after antigen activation.

TH2

Which are benefits of using attenuated vaccines?

The pathogen is most "real" to the immune system They confer longer lasting immunity

Which characteristics of antigens and PAMPs are similar?

They are parts of foreign cells They provoke a reaction by the white blood cells of the host

Antigen binding sites are considered to be highly _________ in amino acid sequence and thus shape.

variable

MHC class I molecules on host cells display unique characteristics of self which is important to the process of _____.

tissue rejection

A measure of antibody level in a patient's serum is called ________.

titer

The concentration of antibodies in serum is expressed as the _________

titer

An antibody has a symmetrical ___ shape.

Y

Since superantigens are potent stimulators of T cells, their presence can result in ______.

a huge release of cytokines with deleterious effects cell death

Current vaccines include __________ vaccines made from capsule polysaccharides to protect against meningitis and pneumonia.

acellular

Vaccines in current use include ________ vaccines that include capsular polysaccharides or proteins.

acellular

B and T lymphocytes provide protection against specific antigens as part of ___________ immunity.

acquired

One outcome of vaccination is the stimulation of artificial ___________ immunity.

active

The result of the body's response to exposure to antigen is called ________ immunity.

active

____________ immunity is the result of the body's response to antigen.

active

The third line of defense, also known as ________ immunity provides long-term protection against foreign antigens encountered through infection or vaccination.

adaptive acquired

In immunology, a chemical vehicle that enhances antigenicity, presumably by prolonging antigen retention at the injection site, is called a(n) ________.

adjuvant

__________________ is a chemical vehicle that is mixed with an antigen preparation to enhance its immunogenicity which is usually due to increased persistence of the antigen.

adjuvant

The aggregation (or clumping) by antibodies of whole cells or similar-sized particles is called ________.

agglutination

Different host cell surface receptors can be involved in a wide range of significant roles such as ______.

aiding in cellular development attachment to foreign antigens receiving and transmitting chemical messages binding to self molecules

An antigen that provokes an allergic reaction is called a(n) ________.

allergen

_______________ is a type of antigen that provokes an allergic response.

allergen

A(n) ______________ is an antigen that is present in some but not all members of a species.

alloantigen

An antigen that is present in some but not all members of the same species is called a(n) ________.

alloantigen

Antigen binding sites are highly variable from one antibody to another. This is due to high variability of the__________ acid content that makes up the hypervariable region.

amino

The high level of variability in antigen binding sites of different antibodies is due to high variability of the ________ composition (sequence) that makes up the variable region.

amino acid

The ________________ response is also called the secondary response and it results in a rapid increase in antibody production due to the activation of memory cells upon interacting with a previously seen antigen.

anamnestic

Antibody-rich serum derived from the blood of animals (deliberately immunized against infectious or toxic antigen) or from people who have recovered from specific infections is called ________.

anitserum

Activated B cells (plasma cells) secrete immunoglobulins otherwise known as .

antibodies

Plasma B cells produce ____________

antibodies

Plasma cells produce copious amounts of ________.

antibodies

_____________ are the antigen-specific receptors on B cells.

antibodies

Following stimulation by antigen, B cells differentiate either into plasma cells, which produce and secrete ______________, or into ____________ cells, which will react rapidly if the antigen is encountered at some point in the future.

antibodies, memory

Plasma cells secrete immunoglobulins called ________.

antibody

A molecule that induces a specific immune response is known as a(n) __________.

antigen

A(n) _____________ is also called an immunogen and induces a specific immune response.

antigen

According to the clonal selection theory, each distinct lymphocyte has an ability to recognize only one specific ___________

antigen

Each genetically distinct lymphocyte has the ability recognize one specific ________.

antigen

Once naive B cells have homed in on and attached to secondary lymphoid tissues, they are able to come into contact with ________ that enters from circulation or fluids.

antigen

The main functions of IgD are to serve as an ____________ receptor on the surface of B cells and to trigger B-cell activation.

antigen

The principal activity of an antibody is to unite with, immobilize, call attention to, or neutralize the ___________ which is complementary to its receptor.

antigen

Visualizing the Y shaped antibody structure, the _________ binding sites are found at the ends of the arms.

antigen

In most specific immune responses, antigen must be processed and presented by ____________-_______________ cells.

antigen-presenting

Polysaccharides from the capsule of Haemophilus influenzae are too small to trigger an immune response. These would be described as ______.

antigenic but not immunogenic

The property of a substance to stimulate a specific immune response such as antibody formation is called ________.

antigenicity

___________ are foreign molecules that elicit a specific immune response.

antigens

_________ is the term given to antibody rich serum which can be used diagnostically and therapeutically.

antiserum

A type of antibody that neutralizes bacterial exotoxins is called a(n) ______.

antitoxin

A(n) ____________ is a special type of antibody that neutralizes bacterial toxins.

antitoxin

T cytotoxic cells initiate ________________ or programmed cell death in their target cells.

apoptosis

________ is the genetically programmed death of cells that is both a natural process of development and the body's means of destroying abnormal or infected cells.

apoptosis

Immunity that is induced as a medical intervention, either by exposing an individual to an antigen or by administering an immune substance such as antiserum is called ________ immunity.

artificial

Immunotherapy is _______________ passive immunization with antibodies.

artificial

___________ immunity results when a person is given a vaccination or receives premade antibodies through medical intervention.

artificial

The immunization with antibodies, also known as immunotherapy, is a form of ________ immunization.

artificial passive

Looking at a Y shaped antibody structure, the antigen binding sites are found ______.

at the end of each of the forks

To reduce the virulence of a pathogenic bacterium or virus by passing it through a non-native host or by long-term subculture is to _________ the organism.

attenuate

_________________ is a process, such as subculturing, that is used to reduce the virulence of a pathogen so it can be used in a live vaccine preparation.

attenuation

Which is the term used to describe a compound which induces autoimmune disease?

autoantigen

_______________ is a name given to antigens which induce autoimmune disease.

autoantigen

After B cells have homed in on secondary lymphoid tissues, they are available to bind antigens that enter from circulation or fluids.

true

The activation of B cells involves ______.

binding of antigen clonal selection.

T helper 1 cells activate macrophages by ______.

both direct receptor contact and indirectly with cytokines

The disadvantages associated with using live attenuated vaccines include ______.

can be transmitted to others possibility of mutating back to a virulent strain requiring special storage facilities

Which is NOT a benefit of using attenuated vaccines?

cannot cause infection

Foreign antigens recognized by the immune response include ______.

cells from other humans whole microbes or their parts substances such as proteins from other humans cells or substances from animals

A conceptual explanation for the development of lymphocyte specificity and variety during immune system maturation is known as the _________ theory.

clonal selection

The __________ _____________ theory is a conceptual explanation for the development of lymphocyte specificity and variety during immune system maturation.

clonal selection

The activation of B cells by antigen involves the ______ ______ of a B cell bearing the complementary antigen-specific receptor.

clonal selection

A group or colony of genetically identical cells is called a(n) ________.

clone

The multiplication of lymphocytes upon encountering antigen results in production of a , ___________ or group of genetically identical cells.

clone

Upon encountering antigen, lymphocytes undergo differentiation and proliferation resulting in production of a group of genetically identical cells called ________.

clones

Looking at the structure of an antibody, you will find ______.

constant regions 2 identical heavy chains 2 identical light chains

The secondary lymphoid tissues are ______ with new B and T cells.

continuously supplied

The ________ fragment is the portion of an antibody that does not bind to antigen.

crystallizable

The segment of the antibody that does not bind antigen is called the _______________ _____________ or the Fc fragment.

crystallizable fragment

T helper cells activate macrophages directly through receptor contact and indirectly through the release of ___________

cytokines

The CD8 coreceptor is expressed on ______ T cells.

cytotoxic

The CD8 coreceptor is expressed on ____________ T cells.

cytotoxic

The CD8 coreceptor is found on the surface of which cell type?

cytotoxic T cells

_________________ is the ability of certain T cells to kill a specific target cell such as an infected cell or a cancer cell.

cytotoxicity

Along with B cells, ______ can serve as APCs for T cell activation.

dendritic cells and macrophages

True or false: At the beginning of an immune response, most antibodies produced are IgM but as the response progresses, you see mainly IgG antibodies or some other class being produced.

true

Activation signals received from the T cells cause the activated B cell to ______.

enlarge proliferate differentiate

A(n) ___________ is the molecular fragment of an antigen that defines its specificity and triggers an immune response.

epitope

The precise molecular group of an antigen that defines its specificity and triggers an immune response is called a(n) _____.

epitope

Individual antigens will have numerous locations or ______ that will elicit separate immune responses.

epitopes

True or false: There is a vaccine for almost all known pathogenic microbes.

false

True or false: Immune system receptors are involved in binding to MHC molecules.

true

True or false: The clonal selection theory states that lymphocyte specificity is genetically preprogrammed.

true

An important characteristic of an antigen is that it be perceived to be ________.

foreign

Antigens are ________ molecules that stimulate a specific immune response.

foreign

One important characteristic of an antigen is that it be perceived as ______________meaning that it is not a normal constituent of the body.

foreign

Antigens and PAMPs are similar in that both can provoke a reaction by the ______ of the host.

white blood cells