Question 1

Which of the following statements about the immune system is false

Accepted Answer

A)   the immune system has mobile elements
B)   immune system cells travel exclusively in the circulation
C)   the immune system protects against invasion by other life forms
D)   immune system cells intercommunicate B

Question 2

Immune cell types are fundementally the result of

Accepted Answer

A)   distinct stem cell types
B)   somatic mutations involving many genes
C)   only slight differences in dynamic patterns of gene expression
D)   genome wide DNA rearrengemnt C

Question 3

Leukocytes move throughout the body thus making it possible for

Accepted Answer

A)   naive lymphocytes to migrate into all tissues
B)   lymphocytes to become activated by encountering antigen in the circulation
C)   leukocytes to enter the lymphatic system first and then move into the tissues
D)   lymphocyte activation to occur in the lymph nodes D

Question 4

HLA class I molecules play a central role in the activation of

Accepted Answer

A)   natural killer cells
B)   complement
C)   neutrophils
D)   eosinophils

Question 5

Antibodies mediate the humoral immune response and are released from

Accepted Answer

A)   macrophages
B)   plasma cells
C)   T-lymphocytes
D)   mast cells

Question 6

Immune cells recognize the presense of pathogens via

Accepted Answer

A)   pattern recognition receptors (PRRs) 
B)   Toll-like receptors (TLRs) 
C)   receptors that sense heat shock proteins (HSPs) 
D)   all of the above

Question 7

Antigen presentation refers to the process whereby fragments of

Accepted Answer

A)   pathogen proteins only are displayed on HLA molecules
B)   self-proteins are displayed only on HLA class II molecules
C)   self-proteins and pathogen proteins are displayed on HLA molecules
D)   pathogen proteins are displayed only on HLA class I molecules

Question 8

HLA molecules expressed on cell membranes can range from three to twelve because

Accepted Answer

A)   all six maternal and paternal genes are expressed
B)   there are three genes that code for HLA class I molecules
C)   most cells do not express HLA class II molecules
D)   all of the above

Question 9

The T-helper population is diffrentiated into Th1, Th2, Th17, and Treg subtypes which function as follows

Accepted Answer

A)   Th1 and Th17 jointly enhance cell mediated immunity
B)   Tregs enhance inflammatory activity
C)   Th2 act to suppress humoral immunity
D)   none of the above

Question 10

Measurement of immune function in humans relies on

Accepted Answer

A)   samples taken from the peripheral circulation
B)   techniques such as flow cytometry and ELISA
C)   the delayed-type hypersensitivity reaction
D)   all of the above

Question 11

Immune memory

Accepted Answer

A)   refers to the enhanced immune response to reinfection
B)   reflects the enhanced survival of lymphocytes responsive to previously encountered antigen
C)   both a and b
D)   none of the above

Question 12

When naive T-helper lymphocytes bind strongly to antigen in the absence of costimulation they

Accepted Answer

A)   proliferate uncontrollably
B)   transform into a plasma cells
C)   become anergic
D)   enter a state of high activation

Question 13

Cytokines exhibit pleiotropy which means

Accepted Answer

A)   non-redundancy of effect
B)   specificity of effect
C)   receptor independent effect
D)   multipicity of effects

Question 14

The complement system is a component of the

Accepted Answer

A)   adaptive immune system
B)   natural killer cell repetoire
C)   immunoglobulin family
D)   innate immune defenses

Question 15

Inflammation is a process initiated by tissue damage or detection of pathogens which causes

Accepted Answer

A)   local vasodialation
B)   decresed vascular permeability
C)   complement deactivation
D)   all of the above

Question 16

Human Leukocyte Antigen (HLA) System refers to

Accepted Answer

A)   the set of proteins displayed on cell surfaces that act as markers of nonself
B)   the system that recognizes leukocytes
C)   the system that defends against self-antigen
D)   the human counterpart of the major histocompatibility complex

Question 17

Which of the following is not true about the development of the immune system

Accepted Answer

A)   the basic structure of the immune system is present at birth
B)   the complement system develops completely before birth
C)   IgD lymphocytes gradually disappear
D)   a fully competent immune system may not be in place until early adolesence

Question 18

Antigen binding sites of antibody molecules have a diverse structure that is the result of

Accepted Answer

A)   gene diversity
B)   random gene selection
C)   post-transcription rearrangement
D)   gene rearrangement

Question 19

When activated T-helper cells bind to B-lymphocytes displaying the T-cell antigen and release cytokines they cause the B-lymphocyte to

Accepted Answer

A)   become activated and differentiate into memory cells
B)   begin making specific antibody
C)   become anergic
D)   both a and b

Question 20

Healthy humans cells and beneficial microbes

Accepted Answer

A)   are quite distinct from harmful microbes and abnormal cells
B)   share molecular structures with pathogens
C)   are normattly attacked by the immune system
D)   none of the above

Exam 3: Immune System Basics