LU2 Specific Immune Response

1. What is the primary function of the immune system?
   a) Digestion of food
   b) Defense against infections and foreign antigens
   c) Regulation of body temperature
   d) Production of red blood cells

2. Which of the following is a characteristic of the adaptive immune system?
   a) Rapid, non-specific response
   b) No immunologic memory
   c) Specific recognition of pathogens
   d) Only functions at the site of infection

3. Which cells are responsible for adaptive immunity?
   a) Neutrophils and macrophages
   b) B cells and T cells
   c) Erythrocytes and platelets
   d) Dendritic cells and basophils

4. Which component of the immune system is responsible for humoral immunity?
   a) T cells
   b) B cells
   c) Macrophages
   d) Dendritic cells

5. What is the function of memory cells in adaptive immunity?
   a) Present antigens to other immune cells
   b) Engulf pathogens via phagocytosis
   c) Mount a rapid and specific response upon re-exposure
   d) Produce histamine to induce inflammation

6. Where do adaptive immune responses primarily occur?
   a) At the site of infection
   b) In the spleen and lymph nodes
   c) In the bloodstream
   d) In the skin

7. Which cells provide a link between the innate and adaptive immune responses?
   a) Neutrophils
   b) Dendritic cells
   c) B cells
   d) Plasma cells

8. What is the primary function of Major Histocompatibility Complex (MHC) molecules?
   a) Engulf pathogens
   b) Transport immune cells
   c) Present antigens to T cells
   d) Destroy infected cells

9. Which type of MHC molecule presents antigens to CD8+ T cells?
   a) MHC I
   b) MHC II
   c) Both MHC I and II
   d) None of the above

10. Which type of MHC molecule is primarily expressed on professional antigen-presenting cells (APCs)?
    a) MHC I
    b) MHC II
    c) MHC III
    d) Both MHC I and II

11. What type of T cells recognize antigens presented by MHC class I molecules?
    a) CD4+ T cells
    b) CD8+ T cells
    c) Regulatory T cells
    d) Memory B cells

12. What is the function of B cell receptors (BCRs)?
    a) Present antigens to T cells
    b) Bind to specific antigens and initiate immune response
    c) Directly kill pathogens
    d) Activate macrophages

13. What do B cells differentiate into after activation?
    a) Dendritic cells
    b) Plasma cells
    c) Helper T cells
    d) Natural killer cells

14. What is the primary role of plasma cells?
    a) Phagocytosis
    b) Antibody production
    c) Activation of macrophages
    d) Engulfment of pathogens

15. T-cell receptors (TCRs) recognize antigens presented by:
    a) B cells
    b) MHC molecules
    c) Natural killer cells
    d) Platelets

16. What type of antigens do MHC class II molecules present?
    a) Intracellular antigens
    b) Extracellular antigens
    c) Self-antigens
    d) None of the above

17. What is the function of cytotoxic T cells?
    a) Activate B cells
    b) Kill infected host cells
    c) Stimulate macrophages
    d) Produce antibodies

18. Which T-cell subset helps activate B cells to produce antibodies?
    a) CD8+ T cells
    b) CD4+ T cells
    c) Natural killer cells
    d) Regulatory T cells

19. Which cytokine is produced by TH1 cells to activate macrophages?
    a) IL-4
    b) IFN-γ
    c) IL-10
    d) IL-6

20. Which antibody is the first to be produced during an immune response?
    a) IgG
    b) IgA
    c) IgM
    d) IgE

21. What is the main function of IgA antibodies?
    a) Neutralization of viruses
    b) Mucosal immunity
    c) Activation of complement
    d) Promoting allergic responses

22. Which immunoglobulin is involved in allergic reactions?
    a) IgM
    b) IgE
    c) IgA
    d) IgG

23. What is isotype switching?
    a) Change in antibody variable regions
    b) Change in antibody constant regions
    c) Degradation of antibodies
    d) Fusion of B and T cells

24. The process of increasing antibody affinity during an immune response is called:
    a) Clonal expansion
    b) Isotype switching
    c) Somatic hypermutation
    d) Opsonization

25. What is the function of opsonization?
    a) Destroy antibodies
    b) Coat pathogens for easier phagocytosis
    c) Stimulate T-cell production
    d) Prevent antibody binding

26. Which immune cells kill virus-infected cells?
    a) B cells
    b) CD8+ T cells
    c) Basophils
    d) Mast cells

27. Which immune cells are responsible for immunologic memory?
    a) Dendritic cells
    b) Memory B and T cells
    c) Eosinophils
    d) Neutrophils

28. What do TH2 cells mainly defend against?
    a) Intracellular pathogens
    b) Extracellular pathogens
    c) Viruses
    d) Autoimmune diseases

29. What is the primary function of IL-4?
    a) Macrophage activation
    b) B-cell differentiation
    c) Fever induction
    d) Antigen presentation

30. What happens during clonal selection?
    a) T cells migrate to infection sites
    b) Antigen-specific lymphocytes proliferate
    c) Phagocytes engulf bacteria
    d) Red blood cells produce antibodies

31. Which of the following is a secondary immune response characteristic?
    a) Slower response
    b) Stronger and faster response
    c) No memory involvement
    d) Weaker antibody production

32. What does IL-5 stimulate?
    a) Eosinophil activation
    b) Neutrophil production
    c) Basophil degranulation
    d) Dendritic cell maturation

33. What is the function of regulatory T cells?
    a) Promote immune response
    b) Suppress immune response
    c) Activate macrophages
    d) Directly kill pathogens

34. Which immunoglobulin has the longest half-life?
    a) IgA
    b) IgG
    c) IgM
    d) IgE

35. What process allows T cells to recognize a wide variety of antigens?
    a) Opsonization
    b) Antigen processing
    c) Gene rearrangement
    d) Antigen presentation

Answers

1.b, 2.c, 3.b, 4.b, 5.c, 6.b, 7.b, 8.c, 9.a, 10.b, 11.b, 12.b, 13.b, 14.b, 15.b, 16.b, 17.b, 18.b, 19.b, 20.c, 21.b, 22.b, 23.b, 24.c, 25.b, 26.b, 27.b, 28.b, 29.b, 30.b, 31.b, 32.a, 33.b, 34.b, 35.c.