Immune System

Question 1

Lymphocytes which mature in the lymph system (as opposed to in the marrow or thymus) are called _____, and are a part of the non-specific defense system.

Answer 1

natural killer (NK) cells

Question 2

Many cells, after being infected by a virus, manage to secrete _____ which stimulate neighboring cells to resist viral infection and ultimately signal the immune system.

Answer 2

interferons (IFNs)

Question 3

Most _____ is found as a dimer (two stuck together) in body secretions, and helps to _____.

Answer 3

IgA; prevent pathogens from attaching to the body’s surface

Question 4

_____ serves as an antigen receptor for B-cells: it is physically attached to their surface.

Answer 4

IgD

Question 5

_____ is found in barrier regions, bound to mast cells and basophils: antigen binding causes the cells to _____.

Answer 5

IgE; release histamine and other inflammatory chemicals

Question 6

Most antibodies are _____. When bound to an antigen, these are recognized by other components of the immune system, which then _____.

Answer 6

IgG; destroy the object to which it is bound

Question 7

As a pentamer (five units bound together), _____ is the first antibody released by new plasma cells and so can serve as a marker for an active infection.

Answer 7

IgM

Question 8

Without _____ there can be no adaptive immune response.

Answer 8

helper T-cells