1. Adaptive immunity is characterized by which of the following?
A. Rapid, non-specific response.
B. Immediate response to all pathogens.
C. Specificity and immunological memory.
D. Lack of response to self-antigens.
2. What is the role of memory cells in the immune response?
A. To initiate the primary immune response.
B. To directly kill pathogens during the first exposure.
C. To provide a faster and stronger secondary immune response.
D. To suppress the immune response after infection.
3. Which of the following is an example of an autoimmune disease?
A. Tuberculosis.
B. Type 2 Diabetes.
C. Rheumatoid arthritis.
D. Influenza.
4. What is the role of regulatory T cells (Treg cells)?
A. To directly kill infected cells.
B. To enhance antibody production.
C. To suppress or regulate immune responses, preventing autoimmunity.
D. To initiate the inflammatory response.
5. What is the function of cytokines in the immune system?
A. To directly destroy pathogens.
B. To transport oxygen to immune cells.
C. To act as signaling molecules between immune cells.
D. To neutralize toxins in the bloodstream.
6. What is the purpose of inflammation in the immune response?
A. To suppress the immune response.
B. To prevent pathogen entry into tissues.
C. To recruit immune cells to the site of infection and initiate tissue repair.
D. To directly neutralize viral infections.
7. Which of the following is an example of passive immunity?
A. Immunity acquired after recovering from chickenpox.
B. Antibodies transferred from mother to baby through breast milk.
C. Immunity developed after vaccination against polio.
D. The body`s natural response to a bacterial infection.
8. How do cytotoxic T cells (CD8+ T cells) eliminate infected cells?
A. By producing antibodies that neutralize the pathogen.
B. By phagocytosing infected cells.
C. By releasing cytotoxic granules that induce apoptosis (programmed cell death) in infected cells.
D. By activating the complement system to lyse infected cells.
9. What are antigens?
A. Cells that produce antibodies.
B. Proteins that destroy pathogens.
C. Substances that trigger an immune response.
D. Chemicals that neutralize toxins.
10. Cell-mediated immunity is mainly carried out by:
A. Antibodies.
B. Complement proteins.
C. T lymphocytes.
D. B lymphocytes.
11. What is the underlying mechanism of allergies (hypersensitivity)?
A. Overactive innate immunity.
B. Exaggerated adaptive immune response to harmless substances.
C. Deficiency in antibody production.
D. Failure of cell-mediated immunity.
12. Which immune cells are involved in phagocytosis?
A. B lymphocytes and T lymphocytes.
B. Macrophages and neutrophils.
C. Plasma cells and memory cells.
D. Helper T cells and cytotoxic T cells.
13. What is herd immunity?
A. Immunity acquired through natural infection in a large population.
B. Protection of unvaccinated individuals in a population due to high vaccination rates.
C. The ability of an individual to resist multiple infections simultaneously.
D. The decline in immune function in an aging population.
14. Why is immunological memory beneficial for long-term protection against pathogens?
A. Because memory cells directly eliminate pathogens during the primary infection.
B. Because memory cells prevent the initial infection from occurring.
C. Because memory cells allow for a faster and more effective immune response upon re-exposure to the same pathogen.
D. Because memory cells suppress the immune response after the primary infection.
15. What is immunological tolerance?
A. The ability of the immune system to mount a strong response to pathogens.
B. The state of unresponsiveness of the immune system to self-antigens, preventing autoimmunity.
C. The temporary suppression of the immune system after an infection.
D. The enhanced immune response after repeated exposure to an antigen.
16. Consider a scenario where a person receives a blood transfusion with an incompatible blood type. Which type of hypersensitivity reaction is most likely to occur?
A. Type I hypersensitivity (immediate hypersensitivity).
B. Type II hypersensitivity (antibody-mediated cytotoxic hypersensitivity).
C. Type III hypersensitivity (immune complex-mediated hypersensitivity).
D. Type IV hypersensitivity (delayed-type hypersensitivity).
17. What is the role of MHC (Major Histocompatibility Complex) molecules in immunity?
A. To directly kill infected cells.
B. To produce antibodies.
C. To present antigens to T cells.
D. To activate complement proteins.
18. Which of the following is a potential disadvantage of a highly active immune system?
A. Increased susceptibility to infections.
B. Development of autoimmune diseases or allergies.
C. Reduced ability to fight off cancer cells.
D. Inefficient clearance of pathogens.
19. How does HIV (Human Immunodeficiency Virus) primarily affect the immune system?
A. By overstimulating the immune response.
B. By directly attacking and destroying B lymphocytes.
C. By selectively targeting and destroying helper T cells (CD4+ T cells).
D. By enhancing the function of regulatory T cells.
20. Distinguish between primary and secondary lymphoid organs in the immune system.
A. Primary organs activate immune responses, secondary organs filter lymph.
B. Primary organs are where immune cells develop and mature; secondary organs are where immune responses are initiated.
C. Primary organs produce antibodies; secondary organs carry out cell-mediated immunity.
D. Primary organs are involved in innate immunity; secondary organs are involved in adaptive immunity.
21. What type of cells are primarily responsible for humoral immunity?
A. T lymphocytes.
B. B lymphocytes.
C. Macrophages.
D. Neutrophils.
22. What is the primary function of the immune system?
A. To transport oxygen throughout the body.
B. To regulate body temperature.
C. To defend the body against pathogens and diseases.
D. To break down food for energy.
23. Which of the following is NOT a function of antibodies?
A. Opsonization of pathogens.
B. Neutralization of toxins.
C. Directly killing infected cells.
D. Activation of the complement system.
24. Which of the following is an example of innate immunity?
A. Antibody production after vaccination.
B. Skin acting as a physical barrier.
C. Activation of cytotoxic T cells.
D. Development of immunological memory.
25. Which of the following statements accurately describes the difference between a primary and secondary immune response to the same antigen?
A. The primary response is faster and stronger than the secondary response.
B. The secondary response is faster and stronger due to immunological memory.
C. The primary response involves only innate immunity, while the secondary response involves adaptive immunity.
D. There is no significant difference between primary and secondary immune responses.
26. Which type of immune disorder is characterized by the immune system attacking the body`s own tissues?
A. Immunodeficiency.
B. Autoimmunity.
C. Allergy.
D. Infection.
27. What is the complement system?
A. A group of cells that produce antibodies.
B. A series of proteins in the blood that enhance immune reactions.
C. A network of lymphatic vessels that filter pathogens.
D. The primary organ responsible for T cell maturation.
28. Vaccination primarily works by stimulating:
A. Innate immune response.
B. Passive immunity.
C. Active adaptive immunity and immunological memory.
D. Immediate antibody production without memory.
29. What is the role of dendritic cells in initiating adaptive immunity?
A. To produce antibodies directly.
B. To directly kill pathogens by phagocytosis.
C. To capture antigens and present them to T cells in lymph nodes, initiating adaptive immune responses.
D. To suppress inflammatory responses at the site of infection.
30. In the context of organ transplantation, what is the primary immunological challenge?
A. Preventing autoimmune reactions in the recipient.
B. Suppressing the recipient`s immune system to prevent rejection of the transplanted organ.
C. Enhancing the recipient`s innate immunity to fight infections.
D. Stimulating antibody production against the transplanted organ.
