Multiple Choice Questions: Choose the One Best Answer

IMMUNOLOGY MIDTERM EXAM

MULTIPLE CHOICE QUESTIONS: CHOOSE THE ONE BEST ANSWER

1. Which category of hypersensitivity BEST describes symptoms associated with allergic

diseases?

A. Type

B. Type 11

C. Type III

D. Type IV

E. None of the above

2. Which statement BEST describes children with congenital asplenia?

A. frequent episodes of hemolytic anemia

B. Elevated serum gamma globulin'-

C. Increased incidence of bacterial infections

D. Decreased complement component C5a

E. Increased incidence of viral infections

3. Neutrophils are attracted to an infected area by;

A. C3a

B. C5a

C. C2 and C4

D. Factor D

E. IgM

4. Unconjugated, free haptens are classified as:

A. Neither immunogens nor antigens

B. Immunogens

C. Antigens

D. Invitrogens

E. Both immunogens and antigens

5. The T cell receptor:

A. Recognizes nonsequential protein epitopes

B. Has four hypervariable regions that comprise its paratope.

C. Recognizes antigen in the form of peptides bound in the groove on MHC

molecules

D. Recognizes lipids presented by MHC molecules on B cells.

E. Is a trans membrane homodimer composed of two identical disulfide-linked

polypeptide chains.

6. The primary lymphoid organs in humans include:

A. Bone marrow, thymus and lymph node

B. Spleen, thymus and lymph node

C. Fetal liver, thymus and spleen

D. Bursa of Fabricius, liver and spleen

E. Fetal liver, bone marrow and thymus,'

7. Which property best describes NK cells:

A. They synthesize and express mature surface IgG

B. They mature and differentiate in the thymus

C. They non-specifically kill virally infected target cells

D. They suppress B cell responses

E. They aid antigen-stimulated B cells to produce anti body

8. Which of the following complement components or complement receptors is NOT

directly involved in solubilization and clearance of immune complexes?

A. C4b

B. C3b

G. CR1

D. CR3

E. All of the above complement components and receptors are involved in

solubilization and clearance of immune complexes.

9. Which of the following sets of immunoglobulin classes ALL have hinge regions:

A. lgD, IgE and IgG

B. IgA, I gE and IgM

C. IgA, IgD, and IgM

D. IgD, IgG and IgM

E. IgA, IgD and IgG

10. Which statement BEST describes T helper 3 type (Th3) lymphocytes:

A. They give help to D cells to produce IgG2a

B. They primarily secrete TGF-beta upon activation

C. They suppress T helper 1 cells, but do not suppress T helper 2 cells

D. They are the primary T cell involved in delayed type hypersensitive responses

E. They primarily secrete IL-2 and Interferon gamma upon activation

11. All mature T cell receptors form a complex on the surface of T lymphocytes with:

A. CD28

B. CD2

C. CD3

D. ON

E. CD8

12. Which physiochemical forces are involved in antigen-antibody interactions:

A. Magnetic charges, Coomb's forces and hydrophobic bonds.

B. Covalent bonds, electrostatic interaction and hydrogen bonds

C. Hydrophobic bonds, hydrogen bonds and charge-charge interaction

D. Junk bonds, Jail bonds and James bonds

E. Van der W aal's forces, hydrophilic bonds and covalent bonds.

13. Agglutination reactions can exhibit the phenomenon of prozone when:

A. Antibody is in excess of antigen

B. Monoclonal antibody is in excess of polyclonal antibody-

C. Antibody affinity is greater than antibody avidity.

D. Molar concentrations of antibody and antigen are equivalent

E. Antigen is in excess of antibody

14. Which statement is TRUE regarding the complementarity determining regions (CDRs)?

A. The CDRs are important in determining the overall variable region structure, but

are not directly involved in antigen binding.

B. They are located in the CH2 domain of the immunoglobulin heavy chain.

C. V, D, and J gene segments contribute to the diversity of CDR3 in heavy chains

D. The joining of the V and D gene segments is important in determining the

sequence of CDR2.

E. The proteins Rag-1 and Rag-2 are not required for formation of CDR3.

15. The percent of B lymphocytes which differentiateand mature in the thymus is:

A. Less than 1%

B. Greater than 25%

C. Between 10% and 25%

D. Between 5 and 10%

E. Between 1 and 5%

16. Innate immune system components include all of the following EXCEPT:

A. Skin.

B. Salivary lysozyme

C. Alternate complement pathway components

D. Neutrophils

E. Plasma cells

MATCHING: Choose the single best answer. Each answer may be used once,more than once, or not at all.

17. Involves binding of antigen-antibody A. ELISA

complexes to phagocytic cells. B. Precipitation

18. Involves reaction of antigen with C. Hapten inhibition

antibody, and detection with enzyme D. Opsonization

labeled immunoglobulin E. Ouchterlony

19. Requires gel diffusion for

antigen-antibody interactions

20. Which cell populations are BEST characterized by the ability to display high-affinity

surface receptors for IgE?

A. Eosinophils, Mast cells, and T cells

B. Basophils and splenocytes, and B cells

C. Macrophages, Neutrophils, and T cells

D. Basophils, Mast cells, and Eosinophils

E. Neutrophils, Eosinophils, and Macrophages

21. Atopic dermatitis (AD) is a chronic inflammatory skin disease in which T Cells are

induced to secrete cytokines following the highly specific binding between the T cell

receptor (TCR) and the MHC/antigen peptide complex. Which of the following

statements is FALSE regarding MHC-specific T cell activation?

A. The TCR interacts with MHC Class II molecules and a peptide antigen of

approximately 12-25 amino residues.

B. gamma-delta T cells require co-stimulation through binding of the CD4 with the

Fc receptor on the antigen presenting cell.

C. Cytotoxic T lymphocytes recognize antigen presented on infected target cells. f

D. Adhesion molecules aid in the interaction of T helper lymphocytes with antigen

presenting cells.

E. All of the above are true.

22. All of the following affect the antigen-binding region of immunoglobulins EXCEPT:

A. Insertion of nucleotides at the D-J junction by terminal deoxynucleotide transferase

B. Isotype switching

C. Random selection of V, D and J gene segments,

D. Pairing of different heavy and light chain V regions

E. Somatic mutation

23. A Type IV hypersensitivity reaction is characterized by:

A. Neutrophil infiltrate

B. Participation by complement

C. T lymphocyte infiltration

D. Cytotoxic antibody

E. None of the above

24. Cells of the reticuloendothelial system (RES) contribute to immunity against

microorganisms by all of the following means EXCEPT:

A. Intracellular killing of pathogens

B. Recruitment of inflammatory cells

C. Synthesis and secretion of antibodies

D. Presentation of antigen

E Cytokine production

25. C3b is involved in all of the following EXCEPT:

A. Covalent attachment to bacteria

B. Altering vascular permeability

C. Enhancement of humoral immune responses

D. Formation of C5 convertase

E. Opsonization and ptiagocytosis of bacterial pathogens

26. A large body of immunologic, epidemiologic and genetic data indicates that tissue injury

in multiple sclerosis (MS) results from an abnormal immune response to one or more

myelin antigens. Susceptibility may be mediated by the class II MHC genes

themselves, related to the known function of these molecules in the normal immune

response. Regarding the organization of human MHC genes, which is TRUE:

A. The class II region consists of HLA-A, HLA-D, and HLA-C loci.

E. The class II region is subdivided into HLA-DP, HLA-DQ and HLA-DR.

C. The class Ill region encodes for HLA-C.

D. The class III region encodes for Beta-2-Microglobulin.

E. All of the above are false.

27. A 13 year old teenager stung by a bee experiences immediate respiratory distressfollowed by unconsciousness. The underlying mechanism is mediated most likely by.

A. IgA antibody

B. Complement C3a

C. IgM antibody

D. Sensitized T cells

E. IgE antibody

28. Regarding T cell receptor (TCR) gene rearrangement events:

A. If the gamma and delta chain genes do not rearrange successfully, then the

alpha chain genes begin to rearrange.

B. The gamma and delta chain genes rearrange simultaneously

C. If the alpha and beta chain genes do not rearrange successfully, then the delta

chain genes begin to rearrange.

D. The alpha and beta chain genes rearrange simultaneously

E. The TCR genes of mature T cells are all in the germ line configuration.

29. Which statement is TRUE regarding immunoglobulin genes and expression?

A. A single B Dell can express multiple kappa and lambda light chains

simultaneously.

B. The kappa locus undergoes rearrangement first, followed by the lambda and

heavy chain loci.

C. The kappa and lambda light chain loci utilize the same set of V and J gene

segments.

D. The transition from membrane-bound IgG1 to secreted IgG1 expression involves

DNA rearrangement.-

E. Lack of the surrogate light chain protein lambda-5 can arrest B Cell development

and result in immunodeficiency.

30. The MHC Class III genes:

A. Encode complement components

B. Encode Beta-2-Microglobulin

C. Encode proteins structurally similar to Class II molecule

D. Encode proteins structurally similar to Class I molecules.

E. Encode interleukin-1 beta and lymphophilin.

31. Which of the following occurs BEFORE antigen exposure?

A. Coexpression of surface IgM and IgD

B. Somatic hypermutation

C. Differentiation of B cells into plasma cells

D. AffInIty maturation

E. Switching from IgM to IgA1 expression

32. Adjuvants are substances that:

A. Are coupled to haptens to render them antigenic

B. Enhance immune responses

C. Inactivate toxic properties of certain toxins

D. Elicit serum sickness

E. Consist of mixtures of cytokines and interferons

33. Regarding the structure of the MHC Class I molecule:

A. It is composed of two transmembrane polypeptides, each containing two

extracellular domains.

B. The peptide-binding site is shared by the two domains nearest to the cell

membrane.

C. The complex with Beta-2-Microglobulin contains a total of fiveimmunoglobulin-like domains with the Beta-2-Microglobulin juxtaposed near the cell surface membrane.

D. The molecule is expressed at the cell surface in a non-covalent association with an invariant polypeptide.

E. It is a transmembrane polypeptlde containing three intracellular domains alpha 1,

alpha2, and alpha3.

34. Lipopolysaccharide can cause:

A. Both polyclonal and monoclonal stimulation of T cells

B. Monocional stimulation of T cells

C. Polysional stimulation of T cells

D. Monoclonal stimulation of NK cells

E. Polyclonal stimulation of B cells

35. Both C3a and C5a can cause:

A. Production of Factor D

B. Bacterial lysis

C. Smooth muscle contraction

D. Phagocyrtosis of IgA-coated bacteria

E. Aggregation of C2 and C4

36. In the process of antigen presentation, CD4+ T Dells recognize;

A. Exogenous peptides associated with invariant chain Beta-2-Microglobulin.

B. Endogenous peptides associated with MHC class I molecules.

C. Exogenous peptides associated with MHC class I molecules.

D. Endogenous peptides associated with MHC class II molecules.

E. Exogenous peptides associated with MHC class II molecules.

37. A lymph node contains the following:

A. Pacinian corpuscles

B. Parafollicular cells

C. Cortex and medulla

D. Red and white pulp

E. Hassall's corpuscles

38. Which statement below is TRUE:

A. T lymphocytes cellsare derived from pluripotent hematopoietic stem cells in the

bone marrow, and mature in the thymus.

B. Neutrophils developing in the presence of MHC molecules undergo apoptosis.

C. B lymphocyte are derived from pluripotent hematopoietic stem cells in the bone

marrow, and undergo VDJ rearrangement in the spleen and lymph nodes.

D. Myeloid cells undergo clonal selection to give progeny with identical antigenic

specificity.

E. T cell receptor gone rearrangement occurs after encounter with antigen.

39. Synthesis of MHC Class I and Class II molecules occurs:

A. In the phagosome.

B. In the nucleus.

C. In the mitochondria.

D. In the Golgi apparatus.

E. Intherough endoplasmic reticulum.

40. Which factor listed in the groups below will NOT influence outcome of immunization:

A. ABO blood group type

B. Previous exposure to the same antigen

C. Nutritional status

D. Antigen dose

E. HLA type

ANSWERS:

- 1 -