Chapter 42
Binding of IgE antibodies to antigens is associated with immediate hypersensitivity reactions. Which of the following could help minimize these reactions?
Treatment with drugs that prevent IgE from binding to their receptors on basophils and mast cells
Of the white blood cell types, which is not a phagocyte?
Natural killer cells
Which of the following pathogens could not cause human infection and illness?
Bacteriophage
Which of the following properly describes the antibody diversity generated by genomic rearrangements.
Each B cell generates a single rearrangement of the heavy chain and a single rearrangement of the light chain, which combine to make a single antibody variant.
T cells must undergo both positive and negative selection during development. This means that they must:
Recognize and bind to self MHC (major histocompatibility complex) molecules.
Not recognize or bind to self antigens associated with MHC molecules.
Which of the following parts of the complement system would work on bacteria but not work on viruses?
The membrane attack complex
Immunodeficiency can occur in which group of people?
The elderly
HIV-infected individuals
Newborns
Analysis of the site of a wound shows that the tissue is swollen and red, and neutrophils are present and have vesicles containing bacterial cells. Which of the following must have occurred at this wound site?
Mast cells have released histamine.
Toll-like receptors have recognized molecules on bacterial cells.
Extravasation of white blood cells has occurred.
Allergies result when the immune system:
Responds to harmless nonself molecules and cells.
The binding of a phagocyte’s toll-like receptor (TLR) to a foreign cell (for example, a bacterium):
Is a signal for the phagocytic cell to release cytokines to recruit other immune cells.
Acts as a trigger for the phagocytic cell to engulf the bacterium.
Leads to the recruitment of other immune cells.
Which of the statements describes adaptive immunity?
It is the basis for vaccines
Why is it that the secondary response to exposure to an antigen elicits a strong, quicker response to the initial exposure to that antigen?
Upon secondary exposure, more B cells exist that produce antibodies that match the antigen than existed in the first exposure. Many of the B cells that respond on secondary exposure are memory B cells.
Which of the classes of immunoglobulin proteins is associated with allergies?
IgE
The secretion of cytokines is a function of:
Helper T cells
What is the function of a toll-like receptor?
To bind to surface molecules present on pathogens
A macrophage destroys a pathogen by:
Phagocytosis
How do immune cells with sensitivity to self antigens become eliminated?
They undergo cell death
What type of cells are targeted by a cytotoxic T cell?
A virus-infected host cell
MHC class II proteins can be found on the surface of a:
Dendritic cell
The selection and differentiation of B cells during clonal selection occurs by which cellular process?
Mitosis
Clonal selection results in the formation of:
plasma cells
Memory cells.
Cells that secrete antibodies.
