Micro Chapter 15 (Mult Choice + T/F) – Flashcards

The embryonic yolk sac, the liver, and the bone marrow are sites where: A. immune responses to antigen occur B. stem cells give rise to immature lymphocytes C. antigen is filtered from the blood D. antigen is filtered from tissue fluid E. T lymphocytes complete maturation

The progeny cells of a B-cell clone are called: A. antibodies B. sensitized T cells C. activated macrophages D. plasma cells E. Bursa cells

Helper T cells: A. secrete antibodies B. function in allergic reactions C. directly destroy target cells D. suppress immune reactions E. activate B cells and other T cells

Plasma cells: A. secrete antibodies B. function in allergic reactions C. directly destroy target cells D. suppress immune reactions E. activate B cells and other T cells

Cell surface markers involved in immune reactions: A. are the result of genetic expression B. function in recognition of self molecules C. receive and transmit chemical messages among other cells of the system D. aid in cellular development E. all of the choices are correct

The major histocompatability complex is: A. glycoproteins, called MHC antigens, found on all body cells except red blood cells B. a series of genes that code for MHC cell receptors C. found on the third chromosome D. located in the thymus gland E. all of the choices are correct

Class II MHC genes code for: A. certain secreted complement components B. self receptors recognized by T lymphocytes C. all HLA antigens D. receptors located primarily on macrophages and B cells E. all of the choices are correct

Class I MHC genes code for: A. certain secreted complement components B. self receptors recognized by T lymphocytes C. all HLA antigens D. receptors located primarily on macrophages and B cells E. all of the choices are correct

Lymphocytes: A. possess MHC antigens for recognizing self B. have membrane receptors that recognize foreign antigens C. gain tolerance to self by destruction of lymphocytes that could react against self D. develop into clones of B and T cells with extreme variations of specificity E. all of the choices are correct

The monomer subunit of immunoglobulin molecules has all the following except: A. two identical heavy polypeptide chains B. two identical light polypeptide chains C. disulfide bonds between polypeptide chains D. four antigen binding sites E. a variable and constant region on each polypeptide chain

Properties of effective antigens include all the following except: A. foreign to the immune system B. molecular complexity C. large molecules with a minimum molecular weight of 1,000 D. large polymers made up of repeating subunits E. cells or large, complex molecules

Small foreign molecules that are too small by themselves to elicit an immune response are termed: A. antigenic determinant B. hapten C. antigen binding site D. variable region E. none of the choices are correct

Superantigens are: A. body tissues that the immune system mistakes as foreign B. cell markers found in some member of a species but not in other members C. bacterial toxins that activate T cells at a 100 times greater rate than other antigens D. those that evoke allergic reactions E. none of the choices are correct

Antigen presenting cells: A. include dendritic cells B. include macrophages C. engulf and modify antigen to be more immunogenic D. hold and present processed antigen on their cell membrane surface E. all of the choices are correct

Which is incorrect about the Fc region of an immunoglobulin? A. is called the crystallizable fragment B. forms the antigen binding sites C. contains an effector molecule that can bind to cells such as macrophages and mast cells D. contains an effector molecule that can fix complement E. determines the class to which the immunoglobulin belongs

Which process involves antibodies coating microorganisms in order to facilitate phagocytosis? A. neutralization B. opsonization C. complement fixation D. agglutination E. anamnestic response

The immunoglobulin class that has a dimer form found in mucus, saliva, colostrum, and other body secretions is: A. IgA B. IgD C. IgE D. IgG E. IgM

The immunoglobulin class that is the only one capable of crossing the placenta is: A. IgA B. IgD C. IgE D. IgG E. IgM

The immunoglobulin/s found on the surface of B cells is/are: A. IgM only B. IgG only C. IgD only D. IgM and IgD E. Igd and IgE

Monoclonal antibodies: A. originate from a single B cell clone B. have a single specificity for antigen C. are secreted by hybridomas D. are used in immunology lab tests and cancer therapy E. all of the choices are correct

The most significant cells in graft rejection are: A. helper T cells B. suppressor T cells C. cytotoxic T cells D. delayed hypersensitivity T cells E. natural killer (NK) cells

These lymphocytes lack specificity for antigen and are cells that attack cancer cells and virus-infected cells: A. helper T cells B. suppressor T cells C. cytotoxic T cells D. delayed hypersensitivity T cells E. natural killer (NK) cells

These cells carry CD8 receptors and function to inhibit B cells and other T cells: A. helper T cells B. suppressor T cells C. cytotoxic T cells D. delayed hypersensitivity T cells E. natural killer (NK) cells

Cytotoxic T cells: A. are activated by APC-bound antigen B. lack specificity for antigen C. secrete lymphotoxins and perforins that damage target cells D. secrete interleukin-2 to stimulate B and T cells E. all of the choices are correct

An example of artificial passive immunity would be: A. chickenpox infection is followed by lifelong immunity B. chickenpox vaccine triggers extended immunity to chickenpox C. giving a person immune serum globulins to chickenpox virus after exposure to the disease D. a fetus acquiring maternal IgG to the chickenpox virus across the placenta E. none of the choices are correct

Antibody molecules circulate in lymph, blood, and tissue fluids. T/F

Class I, II, and III MHC genes are located on the sixth chromosome of humans. T/F

Human B lymphocytes mature in an intestinal region called the bursa. T/F

Antibodies directed to alloantigen from one organism often cross-react with alloantigens from another organism. T/F

Activation of B cells occurs when antigen binds to B cell surface immunoglobulin receptors. T/F

After secreting antibodies during an immune response, plasma cells then differentiate into memory cells. T/F

The hinge region of an antibody has a hypervariable amino acid region where the antigenic determinant fits. T/F

The structural and functional differences that distinguish immunoglobulin isotypes are due to variations associated with their Fc fragments. T/F

One plasma cell will secrete antibodies of various classes but the antibodies will all have the same specificity. T/F

The albumin fraction of serum separated by electrophoresis will contain most of the antibodies. T/F

The primary B-cell receptor is: a. IgD b. IgA c. IgE d. IgG

In humans, B cells mature in the ______ and T cells mature in the _______. a. GALT, Liver b. bursa, thymus c. bone marrow, thymus d. lymph nodes, spleen

Small, simple molecules are ______ antigens. a. poor b. never c. good d. heterophilic

The cross-linkage of antigens by antibodies is known as: a. opsonization b. a cross-reaction c. agglutination d. complement fixation

T _____ cells assist in the functions of certain B cells and other T cells. a. sensitized b. cytotoxic c. helper d. natural killer

Tc cells are important in controlling: a. virus infections b. allergy c. autoimmunity d. all of these.

Which of the following can serve an antigen-presenting cells (APCs)? a. T cells b. B cells c. macrophages d. dendritic cells e. b, c & d

A vaccine that contains parts of viruses is called: a. acellular b. recombinant c. subunit d. attenuated

Conjugated vaccines combine combine antigens and _________. a. antibodies b. adjuvants c. epitopes d. foreign proteins

Widespread immunity that protects the population from the spread of disease is called: a. seropositivity b. cross-reactivity c. epidemic prophylaxis d. herd immunity

Cell surface markers are also ofter called receptors. T/F

Antibodies are secreted by monocytes. T/F

Vaccination could be described as artificial passive immunity. T/F

IgE antibodies are found in body secretions. T/F

The process of reducing the virulence of microbes so that they can be used in vaccines is called denaturation. T/F