Download 4A-2 Worksheet KEY

BIOL 256 SI, Molly
4/6/16
Unit 4A-2
1.) Antibodies = _immunoglobulins__ = __gamma__ __globulins_
2.) Describe “adaptive immune defense” in other similar terms. (ex: antigen specific)
Antigen specific, systemic, memory, acquired immunity
3.) What is the difference between “humoral immune response” and “cellular immune response”?
Humoral – antibody-mediated (B cells)
Cellular – cell-mediated (T cells)
4.) Define an antigen. Define self-antigen (MHC) cells (include the classes). How are they
similar/different?
Antigen – proteins that aren’t found in the body that provoke immune responses
Self-antigens (MHC) – cells tagged with proteins that let the body know they are “self”
MHC I – all body cells
MHC II – certain immune system cells (B cells, dendritic cells, macrophages)
They both have proteins that tell the body their status, but antigens are not from the body and
self-antigens are from the body.
5.) B and T cells both function in adaptive immune responses, but how do their functions differ?
B cells – produce plasma cells (that secrete antibodies) and memory B cells/ oversees humoral
immunity
T cells – memory T cells, helper T cells, cytotoxic T cells/ oversees cell-mediated immunity
6.) B cells become immunocompetent (mature) in the _____________________, while T cells
become immunocompetent (mature) in the ________________________.
a. Thymus; bone marrow
b. Bone marrow; bone marrow
c. Bone marrow; thymus
d. Thymus; thymus
7.) Describe each of the following classes of antibodies name the class described:
a. IgM – pentamer released by plasma cells during primary immune response
b.
IgD – monomer attached to surface of B cells; important for B cell activation
c. IgG – most abundant and diverse in primary and secondary responses; able to cross
placenta and induce passive immunity
d. IgA – Dimer in secretions (saliva, milk) helping prevent attachment of pathogens to
mucosal surfaces
e. IgE – binds to mast cells and basophils; causes histamine release (in response to
allergies)
8.) How do B cells know what cells need to be cloned during clonal selection? Think about the
substances that are secreted by B cells.
Antibodies are specific to antigens, so antibodies tell the B cells if a cell needs to be destroyed or
cloned.
9.) Cell-mediated immune responses occur when antibodies can’t respond to antigens that are
intracellular. The cells involved in this response are the __T__ cells. There are 2 major classes of
the effector cells (there’s also memory cells, but we’re not talking about those!). Name the two
classes and describe the function of each. Give one way on how you’re going to remember the
difference between the two!
CD4 cells – helper T cells that orchestrate the immune response
CD8 – cytotoxic T cells that destroy cells with foreign antigens