Please Help with ALL or NONE! Thank You! I need to check all my answers. QUESTIO
ID: 271076 • Letter: P
Question
Please Help with ALL or NONE! Thank You! I need to check all my answers.
QUESTION 1
A molecule that normally cannot illicit an antibody response, but can if attached to a larger molecule is called:
A.
hemolysin
B.
supeantigen
C.
NOD
D.
hapten
E.
precipitant
QUESTION 2
MHC as we discussed in class refers to which of the following?
A.
Major Helper Cell
B.
Major Histocompatability Complex
C.
Major Heirachy (of) Complement
D.
Major Histone Complex
E.
Major Humoral Component
QUESTION 3
Which of the following is NOT true regarding the use of the 'Indirect ELISA Technique'?
A.
antigen is bound to the microwell plate
B.
unlabeled antibody binds to the antigen
C.
antibodies to IgG are used
D.
color formation indicates the presence of antigen in the patient's serum
E.
washing with buffer removes unattached antibodies
QUESTION 4
Which statement below is true?
A.
cytotoxic T-cells act directly in destroying antigen-bearing cells ; helper T-cells act indirectly
B.
cytotoxic T-cells act indirectly in destroying antigen-bearing cells ; helper T-cells act directly
C.
both cytotoxic and helper T-cells act directly in destroying antigen-bearing cells
D.
both cytotoxic and helper T-cells act indirectly in destroying antigen-bearing cells
E.
neither cytotoxic nor helper T-cells are involved in destroying antigen-bearing cells
QUESTION 5
What is a primary function of TH2 cells?
A.
they activate Cytotoxic T-cells
B.
they cause B-cells that have bound antigen to proliferate and form plasma cells and memory cells
C.
they stimulate Toll-like receptors
D.
they activate macrophages in the lymph nodes
E.
they help initiate the synthesis of the CD8 complex on cytotoxic T-cells
QUESTION 6
Which of the following is most closely associated with membrane-associated molecules called 'Toll-Like Receptors' (TLRs)?
A.
cell mediated immunity
B.
passive immunity
C.
innate immunity
D.
specific acquired immunity
E.
humoral immunity
QUESTION 7
Cytotoxic T-cells possess the __________ and interact with _________ on the target cell.
A.
CD4 coreceptor; MHC Class I proteins
B.
CD8 coreceptor; MHC Class I proteins
C.
CD4 coreceptor; MHC Class II proteins
D.
CD8 coreceptor; MHC Class II proteins
E.
CD4 and CD8 coreceptors; MHC Class I and MHC Class II proteins
QUESTION 8
The antibody that binds to Mast cells and on a second exposure to its antigen causes the release of Histamine and other pharmacological mediators is:
A.
IgG
B.
IgM
C.
IgA
D.
IgD
E.
IgE
QUESTION 9
Helper T-cells are activated by antigen presented by cells (APCs) that:
A.
have Class I MHCs
B.
have Class II MHCs
C.
have both Class I MHCs and Class II MHCs
D.
have CD4 coreceptors
E.
have CD8 coreceptors
QUESTION 10
a series of proteins that react in a sequential manner with antibody-antigen complexes to amplify antibody activity is called:
A.
toll-like proteins
B.
immunoglobulins
C.
complement
D.
barrel proteins
E.
sero proteins
QUESTION 11
In which of the following processes would one expect to find the 'li' protein?
A.
opsonization
B.
presentation of exogenous antigen by Antigen Presenting Cells to cytotoxic T-cells
C.
presentation of exogenous antigen by Antigen Presenting Cells to helper T-cells
D.
presentation of endogenous antigen by Antigen Presenting Cells to cytotoxic T-cells
E.
presentation of endogenous antigen by Antigen Presenting Cells to helper T-cells
QUESTION 12
Human immunoglobulins are classified based on the:
A.
number of constant regions in the light chains
B.
amino acid sequence of the constant regions of the heavy chains
C.
amino acid sequence of the constant regions of the light chains
D.
amino acid sequence of the variable regions of the heavy chains
E.
amino acid sequence of the variable regions of the light chains
QUESTION 13
Which of the following statements is TRUE?
A.
all immunoglobulins are proteins that interact specifically with antigenic determinants
B.
all immunoglobulins have three constant and two variable regions
C.
all immunoglobulins have four constant and four variable regions
D.
all immunoglobulins have both gamma and alpha heavy chains
E.
all immunoglobulins are produced equally in the primary immune response
QUESTION 14
Patient 'X' is worried that she may have contracted 'nastyitis' and has gone to her doctor (who didn't believe in all the new-fangled DNA testing). The doctor performed a complement fixation test on Ms. 'X's serum. The doctor combined (in proper proportions) the patiehnt's serum, the complement proteins and some antigen from the 'nastyitis' pathogen. After proper incubation the doctor add some red blood cells (RBC) from sheep as well as some antibodies to the sheep's RBC. The RBC did not lyse. What did the doctor tell his patient regarding her condition?
A.
since the RBC did not lyze, the complement fixation test is positive and she has been infected
B.
since the RBC did not lyze, the complement fixation test is negative and she has been infected
C.
since the RBC did not lyze, the complement fixation test is positive and she has not been infected
D.
since the RBC did not lyze, the complement fixation test is negative and she has not been infected
E.
thank's for the complement
QUESTION 15
A T-Cell Receptor (TCR) binds:
A.
a self-MHC only
B.
a non-self peptide only
C.
both a self-MHC and a non-self peptide
D.
neither a self-MHC nor a non-self peptide
E.
a no-self MHC and a non-self peptide
QUESTION 16
the antigen binding site is formed by:
A.
interactions between the variable and constant regions of the heavy chains
B.
interactions between the variable and constant regions of the light chains
C.
interactions between the constant regions of both the heavy chain and the light chain
D.
interactions between the variable regions of both the heavy chain and the light chain
E.
interactions between the constant region of the light chain only and the antigen
QUESTION 17
A cell with MHC I proteins that has been infected by a virus would ultimately cause activation of:
A.
macrophages
B.
cytotoxic T-cells
C.
helper T-cells
D.
plasma cells
E.
lymphoid precursor cells
QUESTION 18
A macrophage has attached to a bacterial cell via the macrophage's IgG and C3b receptors. Which of the following is most likely to happen next?
A.
the bacterial cell will lyse
B.
opsonization
C.
agglutination
D.
clonal selection
E.
neutralization
QUESTION 19
Activated 'B' cells that live only a few days but produce a large amount of antibody are called:
A.
cytotoxic cells
B.
memory cells
C.
killer cells
D.
thymus cells
E.
plasma cells
QUESTION 20
The primary and the secondary immune response is characterized by:
A.
an extended 'lag' period of antibody production on a second exposure to antigen
B.
production of IgA in the secondary response rather than IgM
C.
a higher and longer lasting IgG titer in the secondary response than seen during the primary response
D.
an inflammation of the skin
E.
production of IgE in the primary response rather than IgM
A.
hemolysin
B.
supeantigen
C.
NOD
D.
hapten
E.
precipitant
Explanation / Answer
1. The answer is D, Haptin. Haptin is an incomplete antigen, that can initiate an immune response only when attached to a larger molecule (carrier).
2. The answer is B. MHC stands for Major Histocompatability Complex, which refers to cell surface proteins which bind to antigens and display them to T cells for recognition.
3. The answer is C. Specific antibodies to IgG are not used. Specific antibody that bind to the particular antigen are used.
4. The answer is A. Cytotoxic T cells act directly in destroying antigen-bearing cells, whereas helper T-cells do so indirectly. When TC cell is exposed to infected cells, cytotoxins perforin, granzymes, and granulysin are released by it. These enter the cytoplasm of the cell and initiate apoptosis. TH cells help in the activation of TC cells.
5. The answer is B. TH2 cells cause B-cells that have bound antigen to proliferate and form plasma cells and memory cells.
6. The answer is C. Toll-Like Receptors (TLRs) are bound to sentinel cells (like macrophages and dendritic cells) that are important in innate immunity.
7. The answer is B. Cytotoxic T-cells possess the CD8 coreceptor and interact with MHC Class I proteins on the target cell.
8. The answer is E. IgE, produced by plasma cells, is coated onto mast cells. It is important in Type I hypersensitivity.
9. The answer is B. Helper T-cells are activated by antigen presented by cells (APCs) that have Class II MHCs. Class II MHCs are only found on specialized APCs like B cells, dendritic cells and macrophages.
10. The answer is C. Complement proteins are plasma proteins activated by the presence of pathogen/ antibodies, which leads to a cascade of reactions in order to amplify antibody activity.
11. The answer is C. "li" protein refers to class II MHC proteins. These are found on APCs. So, after endocytosing foreign material, the class II MHC proteins are responsible for the presentation of exogenous antigen by Antigen Presenting Cells to helper T-cells.
12. The asnwer is B. Human immunoglobulins are classified based upon the differences in the sequence of amino acids in the constant region of the heavy chains.
17. The answer is B. A cell with MHC I proteins that has been infected by a virus would ultimately cause activation of cytotoxic T cell.
19. The answer is E. Plasma cells are activated B cells that secrete large amounts of antibodies.
20. The answer is A, an extended 'lag' period of antibody production on a second exposure to antigen.