Which of the following statements about T cells is true:
Anonymous Quiz
24%
They mature in bursa of Fabricius or bursal equivalent
0%
They are found in the red pulp of the spleen
0%
They are progenitors of plasma cells
76%
They are involved in cell mediated and humoral immunity
The correct sequence of events in activation of T cells is:
Anonymous Quiz
24%
Activation, differentiation, proliferation
0%
Differentiation, proliferation, activation
24%
Maturation, Differentiation, activation
52%
Activation, proliferation, differentiation
A lymphocyte which has undergone activation, proliferation and differentiation:
Anonymous Quiz
0%
is now called a naive lymphocyte
0%
Can deal with many dangerous pathogens
5%
Stays in the lymph node to deal with pathogans that enter it
95%
is now an effector cell
Comparing BCR and TCR, which statement is TRUE?
Anonymous Quiz
5%
The B and T cell receptors become released into the surroundings
11%
bIn contrast to BCR, TCR has 2 antigens binding sites
84%
Both are cell surface molecules
0%
They bind to antigens non-specifically
Which statement about clonal selection theory is Correct:
Anonymous Quiz
0%
Every naive lymphocyte has many types of receptors
6%
A clone of cells can recognize different antigens
89%
Only lymphocytes which meet antigens they recognize are activated
6%
The B cell receptor cannot recognize an antigen directly
The following are harmful immune responses EXCEPT:
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26%
Allergy
0%
Autoimmune diseases
11%
Graft rejection
32%
Immunodeficiency
32%
None of the above
Where do lymphocytes undergo activation:
Anonymous Quiz
5%
Bone marrow
0%
Liver
89%
Lymph nodes
5%
Thymus gland
Which feature is characteristic of innate immunity
Anonymous Quiz
88%
It does not increase with repeated exposures.
6%
it is highly specific against a particular pathogen.
0%
It responds to bacteria and fungi, but not viruses.
6%
It takes several days to become fully functional
Concerning natural killer cells, which statement is True:
Anonymous Quiz
65%
They are capable of killing virally-infected cells
6%
They are considered part of the acquired immunity
0%
They are specific in their mechanism of killing
29%
They can phagocytose tumor cells
All of the following contribute to innate immunity EXCEPT:
Anonymous Quiz
74%
Plasma cells
21%
C-Reactive Protein (CRP)
0%
Neutrophils
5%
Type I interferon
All the following are characters of acquired immunity EXCEPT:
Anonymous Quiz
6%
It is associated with development of immunological memory
0%
It involves B and T lymphocytes
89%
It acts early after infection
6%
It is more efficient than innate immunity
Innate soluble defense mechanism includes all the following EXCEPT:
Anonymous Quiz
21%
Lysozyme
16%
Complement
0%
Acute phase proteins
63%
Type II interferon
Which statement is TRUE concerning acute phase protein?
Anonymous Quiz
6%
They disappear from the circulation after onset of infection
63%
Endotoxins may stimulate their production
6%
They are produced by the primary lymphoid organs
25%
Type I IFN is an example of acute phase proteins
Phagocytic cells are characterized by the following EXCEPT:
Anonymous Quiz
61%
Play an important defensive role against established viral infection
6%
Contain digestive enzymes in lysosomes
6%
Have Fc receptors
28%
Produce hydrogen peroxide to kill phagocytosed organisms
A characteristic of the adaptive but not of the innate response is:
Anonymous Quiz
0%
Mechanical barriers
0%
Surface secretions
79%
Clonal expansion of the effector cell
21%
Phagocytosis
All of the following steps are involved in the process of phagocytosis EXCEPT:
Anonymous Quiz
6%
Attachment
0%
Engulfment
17%
Phagolysosome formation
78%
Extracellular killing
All the following statements regarding phagocytosis are true EXCEPT:
Anonymous Quiz
6%
Bacteria are engulfed in a phagosome
83%
Natural killer cells are the most important phagocytic cells
11%
Respiratory burst is lethal to microorganisms
0%
Antibodies or C3b may aid in recognition