1. Which cells are primarily responsible for antibody production?
(A) T-lymphocytes
(B) B-lymphocytes
(C) Macrophages
(D) Neutrophils
2. The immunity present at birth is called:
(A) Acquired immunity
(B) Adaptive immunity
(C) Innate immunity
(D) Passive immunity
3. Which immunoglobulin is most abundant in blood plasma?
(A) IgE
(B) IgA
(C) IgM
(D) IgG
4. The maturation of T-cells occurs in the:
(A) Bone marrow
(B) Thymus
(C) Spleen
(D) Lymph nodes
5. Antigens are substances that:
(A) Destroy antibodies
(B) Stimulate immune response
(C) Cause disease directly
(D) Kill pathogens
6. Which immunoglobulin is present in breast milk?
(A) IgG
(B) IgA
(C) IgE
(D) IgM
7. Which cells act as antigen-presenting cells?
(A) RBCs
(B) Platelets
(C) Macrophages
(D) Eosinophils
8. Immunological memory is associated with:
(A) Innate immunity
(B) Adaptive immunity
(C) Passive immunity
(D) Natural immunity
9. Which type of immunity is acquired through vaccination?
(A) Natural active
(B) Artificial active
(C) Natural passive
(D) Artificial passive
10. The first antibody produced in primary immune response is:
(A) IgA
(B) IgE
(C) IgG
(D) IgM
11. Which organ filters blood and traps antigens?
(A) Thymus
(B) Bone marrow
(C) Spleen
(D) Tonsils
12. Which cells are involved in cell-mediated immunity?
(A) T-cells
(B) Plasma cells
(C) B-cells
(D) Mast cells
13. The basic unit of antibody structure is:
(A) Alpha helix
(B) Beta pleated sheet
(C) Polypeptide chain
(D) Amino acid
14. Which immunoglobulin is involved in allergic reactions?
(A) IgG
(B) IgA
(C) IgM
(D) IgE
15. Complement system helps in:
(A) Blood clotting
(B) Pathogen destruction
(C) Hormone secretion
(D) Digestion
16. Which cells destroy virus-infected cells?
(A) B-cells
(B) Helper T-cells
(C) Plasma cells
(D) Cytotoxic T-cells
17. The process by which pathogens are engulfed is called:
(A) Pinocytosis
(B) Endocytosis
(C) Phagocytosis
(D) Exocytosis
18. Which immunoglobulin can cross the placenta?
(A) IgG
(B) IgM
(C) IgA
(D) IgE
19. Memory cells are formed during:
(A) Primary immune response
(B) Innate immunity
(C) Passive immunity
(D) Inflammation
20. Which cells release histamine?
(A) Neutrophils
(B) Monocytes
(C) Basophils
(D) Lymphocytes
21. Which organ produces all blood cells?
(A) Bone marrow
(B) Thymus
(C) Lymph node
(D) Spleen
22. Which antibody is pentameric in structure?
(A) IgG
(B) IgA
(C) IgE
(D) IgM
23. Active immunity is characterized by:
(A) Immediate protection
(B) No memory cells
(C) Long-lasting protection
(D) Temporary response
24. Which cells are first responders during inflammation?
(A) Lymphocytes
(B) Neutrophils
(C) Monocytes
(D) Basophils
25. Vaccines usually contain:
(A) Antibiotics
(B) Antibodies
(C) Hormones
(D) Weakened antigens
26. Which immunity is transferred from mother to fetus?
(A) Natural active
(B) Artificial active
(C) Natural passive
(D) Artificial passive
27. Major histocompatibility complex (MHC) is involved in:
(A) Blood clotting
(B) Enzyme synthesis
(C) Hormone transport
(D) Antigen presentation
28. Which cells differentiate into plasma cells?
(A) T-cells
(B) NK cells
(C) B-cells
(D) Macrophages
29. Which antibody is mainly present on mucosal surfaces?
(A) IgG
(B) IgA
(C) IgM
(D) IgD
30. The chemical mediators of inflammation include:
(A) Insulin
(B) Thyroxine
(C) Hemoglobin
(D) Histamine
31. Which cells lack a nucleus in humans?
(A) Lymphocytes
(B) Monocytes
(C) Neutrophils
(D) RBCs
32. The specificity of antibodies is due to:
(A) Variable region
(B) Constant region
(C) Heavy chain only
(D) Light chain only
33. Which immunity does not involve antibodies?
(A) Humoral immunity
(B) Cell-mediated immunity
(C) Passive immunity
(D) Artificial immunity
34. Which cells are known as natural killer cells?
(A) T-cells
(B) B-cells
(C) NK cells
(D) Plasma cells
35. The swelling and redness in inflammation are due to:
(A) Decreased blood flow
(B) Increased blood flow
(C) Cell death
(D) Antibody action
36. Which immunoglobulin is least abundant in serum?
(A) IgG
(B) IgA
(C) IgM
(D) IgE
37. Which cells engulf bacteria and debris?
(A) Platelets
(B) Phagocytes
(C) Erythrocytes
(D) Plasma cells
38. The secondary immune response is:
(A) Slower and weaker
(B) Same as primary
(C) Faster and stronger
(D) Absent
39. Which lymphoid organ lacks afferent lymph vessels?
(A) Lymph nodes
(B) Tonsils
(C) Thymus
(D) Spleen
40. Which antibody is found on the surface of B-cells?
(A) IgG
(B) IgA
(C) IgE
(D) IgD
41. Which immunity is short-lived?
(A) Active immunity
(B) Passive immunity
(C) Adaptive immunity
(D) Natural immunity
42. Which cells are involved in allergic reactions?
(A) Eosinophils
(B) Neutrophils
(C) Monocytes
(D) RBCs
43. Antibody-producing cells are also called:
(A) Plasma cells
(B) Memory cells
(C) Helper cells
(D) Cytotoxic cells
44. Which molecule binds antigen on T-cells?
(A) Antibody
(B) Complement
(C) MHC-II
(D) T-cell receptor
45. Which type of immunity develops after infection?
(A) Artificial passive
(B) Artificial active
(C) Natural passive
(D) Natural active
46. Which white blood cells are agranulocytes?
(A) Neutrophils
(B) Eosinophils
(C) Basophils
(D) Lymphocytes
47. The complement system belongs to:
(A) Adaptive immunity
(B) Humoral immunity
(C) Innate immunity
(D) Passive immunity
48. Which immunoglobulin exists as a dimer?
(A) IgA
(B) IgG
(C) IgM
(D) IgE
49. Which cells coordinate immune responses?
(A) Cytotoxic T-cells
(B) Helper T-cells
(C) B-cells
(D) NK cells
50. Which term refers to resistance against disease?
(A) Pathogenicity
(B) Allergy
(C) Infection
(D) Immunity