A Treg cell deficiency could result in

• transplant rejection.
• increased severity of bacterial infections.
• increased number of viral infections.
• increased number of bacterial infections.
• autoimmunity.

Autoimmunity

ADCC is a process that is most effective in destroying

• bacterial pathogens.
• bacterial toxins.
• prions.
• extracellular viruses.
• eukaryotic pathogens.

Eukaryotic pathogens.

An antibody's Fc region can be bound by

• macrophages.
• B cells.
• T helper cells.
• antibodies.
• CTLs.

Macrophages

CD4⁺ T cells are activated by

• cytokines released by dendritic cells.
• interaction between CD4⁺ and MHC II.
• interaction between TCRs and MHC II.
• cytokines released by B cells.
• complement

Interaction between CD4+ and MHC II

IL-2, produced by T_H cells,

• causes phagocytosis.
• activates antigen-presenting cells.
• stimulates T_H cell maturation.
• activates macrophages.
• activates T_C cells to CTLs.

Stimulates T_h cell maturation

The antibodies found in mucus, saliva, and tears are

• IgG.
• IgM.
• IgA.
• IgD.
• IgE.

I_gA

The antibodies that can bind to large parasites are

• IgG.
• IgM.
• IgA.
• IgD.
• IgE.

I_gE

The specificity of an antibody is due to

• the constant portions of the H and L chains.
• the variable portions of the H and L chains.
• its valence.
• the H chains.
• the L chains.

the variable portions of the H and L chains

Thymic selection

• destroys B cells that make antibodies against self.
• destroys T cells that do not recognize self-molecules of MHC.
• destroys MHC molecules.
• activates B cells.
• destroys CD4⁺ cells that attack self.

destroys T cells that do not recognize self-molecules of MHC

What type of immunity results from recovery from mumps?

• innate immunity
• naturally acquired active immunity
• naturally acquired passive immunity
• artificially acquired active immunity
• artificially acquired passive immunity

naturally acquired active immunity

What type of immunity results from vaccination?

• innate immunity
• naturally acquired active immunity
• naturally acquired passive immunity
• artificially acquired active immunity
• artificially acquired passive immunity

artificially acquired active immunity

When an antibody binds to a toxin, the resulting action is referred to as

• apoptosis.
• opsonization.
• agglutination.
• neutralization.
• ADCC.

neutralization

Which of the following WBCs are NOT lymphocytes?

• NK cells
• B cells
• helper T cells
• M cells
• cytotoxic T cells

M cells

Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens?

• pili
• flagellum
• capsule
• plasmid
• ribosome

capsule

Which of the following cells is NOT an APC?

• macrophages
• dentritic cells
• natural killer cells
• mature B cells

natural killer cells

Which of the following destroys virus-infected cells?

• T_reg
• B cells
• CTL
• dendritic cells
• T_H
• None of the answers is correct; all of these are APCs.

CTL

Which of the following is the best definition of epitope?

• specific regions on antigens that interact with antibodies
• specific regions on antigens that interact with T-cell receptors
• specific regions on antigens that interact with haptens
• specific regions on antigens that interact with perforins
• specific regions on antigens that interact with MHC class molecules

specific regions on antigens that interact with antibodies

Which of the following recognizes antigens displayed on host cells with MHC II?

• basophil
• B cell
• T_C cell
• T_H cell
• natural killer cell

T_h Cell

Which of the following statements is FALSE?

• The Fc region attaches to a host cell.
• The constant region of a heavy chain is the same for all antibodies.
• The variable region of a light chain is partially responsible for binding with antigen.
• The variable region of a heavy chain is partially responsible for binding with antigen.
• All of the answers are correct.

the constant region of a heavy chain is the same for all antibodies

Which one of the following causes transmembrane channels in target cells?

• granzymes
• perforin
• hapten
• IL-2
• IL-1

perforin