Ch 35 Review

From which of the following conditions would an AIDS patient be least likely to suffer? tuberculosis yeast infections of mucous membranes rheumatoid arthritis Kaposi's sarcoma or other cancers pneumonia

rheumatoid arthritis

Which of the following statements correctly describes the main difference between innate immunity and adaptive immunity? Innate immunity relies on phagocytes to destroy pathogens, whereas adaptive immunity does not involve phagocytes. Innate immunity recognizes molecules common to a set of pathogens, whereas adaptive immunity reacts to specific microbes on the basis of their unique antigens. Innate immunity responds only to free pathogens in a localized area; adaptive immunity responds only to pathogens that have entered body cells. Innate immunity involves only leukocytes, whereas adaptive immunity involves only lymphocytes. Complement proteins participate in adaptive immunity but not in innate immunity.

Innate immunity recognizes molecules common to a set of pathogens, whereas adaptive immunity reacts to specific microbes on the basis of their unique antigens.

Which of the following statements about humoral immunity is correct? It is mounted by lymphocytes that have matured in the thymus. It is a form of passive immunity produced by vaccination. It defends against free pathogens with effector mechanisms such as neutralization, stimulation of phagocytosis, or complement activation. It protects against pathogens that have invaded body cells as well as against cancer cells. It requires recognition of class I MHC molecule-antigen complexes to activate its effector mechanism.

It defends against free pathogens with effector mechanisms such as neutralization, stimulation of phagocytosis, or complement activation.

Which of the following conditions is not considered a disease or malfunction of the immune system? allergic anaphylactic shock MHC-induced transplant rejection type I diabetes lupus and multiple sclerosis AIDS

MHC-induced transplant rejection

What accounts for the huge diversity of antigens to which B cells can respond? B cells can be antigen-presenting cells when they take in antigens and display fragments in their class II MHC molecules. B cells have thousands of copies of antibodies bound to their plasma membranes. The recombination within light and heavy chain genes during development results in millions of possible antigen receptors. The antigen-binding sites at the arms of the molecule can assume a huge diversity of shapes in response to the specific antigen encountered. The antibody genes have millions of alleles.

The recombination within light and heavy chain genes during development results in millions of possible antigen receptors.

What do some antibodies, T cell receptors, and MHC molecules have in common? They are found exclusively in cells of the immune system. They are all part of the complement system. They are antigen-presenting molecules. They are involved in the cell-mediated immune response. They are or can be membrane-bound proteins.

They are or can be membrane-bound proteins.

Which of the following statements is not true of Toll-like receptors? They are located on phagocytic white blood cells. They resemble Toll, an activator of innate immunity in insects. They recognize molecules specific to individual pathogens. TLR proteins may be located on the plasma membrane or inside vesicles of immune cells. They trigger innate immune responses.

They recognize molecules specific to individual pathogens.

Which of the following cells would release interferon? a cell infected by a virus a macrophage that has become an antigen-presenting cell a helper T cell bound to an antigen-presenting cell an injured endothelial cell of a blood vessel a mast cell that has bound an antigen

a cell infected by a virus

Which of the following destroys a target cell by phagocytosis? a cytotoxic T cell a natural killer cell complement proteins a neutrophil a helper T cell

a neutrophil

In neutralization, __________. a flood of histamines is released and may result in anaphylactic shock antibodies coat microorganisms and help phagocytes bind to and engulf the foreign cell a set of complement proteins lyses a hole in a foreign cell's membrane antibodies coat proteins on the surface of a virus, preventing infection of a host cell V gene segments and J gene segments are joined by recombinase

antibodies coat proteins on the surface of a virus, preventing infection of a host cell

Which of the following defense mechanisms is incorrectly paired with its function? cytokines—attract phagocytes in the inflammatory response histamine—causes blood vessels to dilate fever—may stimulate phagocytosis lysozyme—attacks the cell wall of viruses gastric juice—kills bacteria in the stomach

lysozyme—attacks the cell wall of viruses

Which of the answer lists places the following steps in the helper T cell activation of cell-mediated and humoral immunity in the correct order? 1. Macrophage and helper T cell secrete cytokines. 2. Macrophage engulfs pathogen and presents antigen in class II MHC. 3. Plasma cells secrete antibodies, and cytotoxic T cells attack cells with class I MHC molecule-antigen complex. 4. T cell receptor recognizes class II MHC molecule antigen complex. 5. Activated B cells produce plasma cells and memory cells, and activated T cells produce cytotoxic T cells and memory cells.

2, 4, 1, 5, 3

In which of the following circumstances would a B cell display antigens to a T cell? A B cell takes in a few antigen molecules and displays them in class II MHC molecules to activated helper T cells. Or, after being infected by a virus, a B cell displays viral peptides it has synthesized to cytotoxic T cells in its class I MHC molecules. A B cell engulfs bacteria and displays bacterial peptide antigens in class II MHC molecules to helper T cells. A B cell takes in a few antigen molecules and displays them in class II MHC molecules to activated helper T cells. A B cell binds free antigens and displays them to helper T cells while they are still attached to B cell antigen receptors. After being infected by a virus, a B cell displays viral peptides it has synthesized to cytotoxic T cells in its class I MHC molecules.

A B cell takes in a few antigen molecules and displays them in class II MHC molecules to activated helper T cells. Or, after being infected by a virus, a B cell displays viral peptides it has synthesized to cytotoxic T cells in its class I MHC molecules.

A secondary immune response is more rapid and effective than a primary immune response because __________. chemical signals cause the rapid accumulation of phagocytic cells helper T cells are available to activate other white blood cells histamines cause rapid vasodilation the second response is an active immunity, whereas the primary one is a passive immunity memory cells respond to the pathogen and rapidly proliferate into effector cells

memory cells respond to the pathogen and rapidly proliferate into effector cells

Major histocompatibility complex molecules __________. present antigen fragments on infected cells All of the listed responses are correct. are a collection of cell surface proteins are involved in the ability to distinguish self from nonself may trigger T cell responses after transplant operations

All of the listed responses are correct.

Which of the following statements best describes an insect's immune system? Insects produce antimicrobial peptides in response to the binding of recognition proteins to macromolecules from a broad class of pathogens. Insects rely on the barrier defense of an exoskeleton. All of the listed responses are part of an insect's innate immunity. Lysozyme attacks bacterial cell walls, protecting an insect's digestive system. Hemocytes can carry out phagocytosis of bacteria and foreign substances.

All of the listed responses are part of an insect's innate immunity.

In an adaptive immune response, a dendritic cell __________. releases cytokines to activate B cells to produce clones of plasma cells activates humoral and cell-mediated immunity by releasing interferons after engulfing a virus activates complement proteins binds to an accessory protein on cytotoxic T cells to activate their production of toxic compounds presents peptide antigens of an engulfed pathogen in its class II MHC molecules to helper T cells, and releases cytokines

presents peptide antigens of an engulfed pathogen in its class II MHC molecules to helper T cells, and releases cytokines

Clonal selection is responsible for the __________. formation of cell cultures in the commercial production of monoclonal antibodies recognition of class I MHC molecules by cytotoxic T cells rearrangement of antibody genes for the light and heavy chains proliferation of effector cells and memory cells specific to an encountered antigen transformation of a clone of helper T cells into cytotoxic T cells keyed to a specific antigen

proliferation of effector cells and memory cells specific to an encountered antigen

Which of the following best describes the relationship between antibodies and complement? They are both produced by plasma cells. They are both involved in innate defenses. Complement proteins tag foreign cells for destruction; antibodies destroy cells. Antibodies bound to antigens on a pathogen's membrane may activate complement proteins to form a pore in the membrane, causing the cell to swell and lyse. They are both coded for by genes that have hundreds of alleles.

Antibodies bound to antigens on a pathogen's membrane may activate complement proteins to form a pore in the membrane, causing the cell to swell and lyse.

Antibodies are __________. proteins embedded in T cell membranes proteins or polysaccharides usually found on the surface of invading bacteria proteins that consist of two light and two heavy polypeptide chains proteins circulating in the blood that may tag foreign cells for complement destruction proteins circulating in the blood that may tag foreign cells for complement destruction; they are also proteins that consist of two light and two heavy polypeptide chains

proteins circulating in the blood that may tag foreign cells for complement destruction; they are also proteins that consist of two light and two heavy polypeptide chains