FREE BIOLOGY AND STUDY GAMES ABOUT IMMUNE

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FREE BIOLOGY AND STUDY GAMES ABOUT IMMUNE

SYSTEM CH 21 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -251 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: When is B-defensin output increased dramatically, to control bacterial and fungal colonization?

Answer:

when the mucosal surface is abraded or penetrated and tissues become inflamed

Question 2: What is the most common and the most problematic graft type?

Answer:

allograft, with organ usually from a living human donor, (kidney, live, bone marrow) or one who has just died (heart or lung) Question 3: Of foreign proteins, many large polysaccharides, and some lipids and nucleic acids, which of these complete antigens are the strongest?

Answer:

proteins

Question 4: When is the only time antibodies invade solid tissues?

Answer:

when a lesion is present

Question 5: What are the 3 crucial cell types of the adaptive immune system that have 2 distinct populations of lymphocytes, and antigen-presenting cells (APCs)?

Answer:

B lymphocytes or B cells - oversee humoral immunity T lymphocytes or T cells - non antibody producing lymphocytes that constitute the cell-mediated arm of adaptive immunity Question 6: Interferons have an antiviral effect and also activate ________ and mobilize ____ cells.

Answer:

macrophages; NK

Question 7: Where are class II MHC proteins typically found?

Answer:

on surfaces of cells that present antigens to helper T cells: dendritic cells, macrophages, and B cells Question 8: What is the constraint of the helper and cytotoxic T cells called, that helps the class of MHC protein deliver the activation signal?

Answer:

the MHC restriction

Question 9: What is IL-2?

Answer:

a key growth factor that sets up a positive feedback cycle that encourages activated T cells to divide even more rapidly Question 10: What engulf antigens and place their fragments on the surface of their cells to "flag" the T-cells that their defensive actions are needed by the body

Answer:

Macrophages and phagocytes Question 11: What do some consider to be a 5th cardinal sign of acute inflammation?

Answer:

impairment of function

Question 12: What 3 beneficial effects does the inflammatory response provide?

Answer:

1) prevents spread of damaging agents to nearby tissues

2) disposes of cell debris and pathogens

3) sets the stage for repair Question 13: What is it called when lymphocytes themselves rather than antibodies defend the body?

Answer:

cellular immunity or cell-mediated immunity, because the protective factor is living cells

Question 14: The spleen acts as a filter to trap what?

Answer:

bloodborne antigens Question 15: What is a troublesome small molecule that links up with the body's own proteins?

Answer:

hapten, or incomplete antigen Question 16: What is the step called complement fixation in the classical pathway complement activation method?

Answer:

the binding of antibodies to the invading organisms and the subsequent binding of C1 to the microorganism-antibody complexes

Question 17: What are the 2 major types of T cells and what do they do?

Answer:

CD4 cells; primarily helper T cells (TH) CD8 cells; cytotoxic T cells (Tc), which destroy any cells that harbor anything foreign Question 18: What is provided by B cells present in the body's 'humors', or fluids (blood, lymph)?

Answer:

humoral immunity or antibody-mediated immunity

Question 19: The first encounter between an immunocompetent but naive lymphocyte and an invading antigen, usually takes place in the spleen or lymph node or any lymphoid tissue is called what?

Answer:

the antigen challenge

Question 20: What is the biological role and location of IgG?

Answer:

it is the most abundant antibody in plasma and the only Ig class that crosses the placental barrier Question 21: What is the process called when complement proteins or antibodies coat foreign particles to make adherence more probable and more efficient?

Answer:

opsonization Question 22: What is a unique group of defensive cells that can lyse and kill cancer cells and virus-infected body cells before the adaptive immune system is activated?

Answer:

natural killer (NK) cells Question 23: What is the important role of class I MHC proteins in the immune response?

Answer:

They provide the means for signaling to cytotoxic T cells that infectious microorganisms are hiding in body cells Question 24: Plasma cells secrete antibodies at the rate of 2000 molecules per second for 4-5 days then die

Answer:

true

Question 25: What are IFNs?

Answer:

a family of related proteins produced by a variety of body cells, each having a slightly different physiological effect.