Đề thi, bài tập trắc nghiệm online Miễn dịch – Nhiễm trùng – Đề 4

1. What is the role of the complement system in immunity?

A. To produce antibodies.

B. To directly kill virus-infected cells.

C. To enhance phagocytosis, promote inflammation, and directly lyse pathogens.

D. To regulate body temperature during infection.

2. Interferons are cytokines primarily produced in response to:

A. Bacterial infections

B. Viral infections

C. Fungal infections

D. Parasitic infections

3. Antibiotic resistance occurs when:

A. The body becomes resistant to antibiotics.

B. Bacteria develop mechanisms to survive antibiotic treatment.

C. Viruses become resistant to antibiotics.

D. Fungi become resistant to antibiotics.

4. What is the 'hygiene hypothesis'?

A. The idea that excessive cleanliness in early childhood may increase the risk of allergic diseases.

B. The importance of maintaining good personal hygiene to prevent infections.

C. The theory that vaccines are unnecessary if hygiene is maintained.

D. The concept that only poor hygiene leads to infections.

5. Which of the following is an example of a physical barrier in the innate immune system?

A. Antibodies

B. Skin

C. T cells

D. Complement system

6. Which of the following best describes 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.

D. To digest food and absorb nutrients.

7. What is the role of histamine in the inflammatory response?

A. To decrease blood vessel permeability.

B. To cause vasoconstriction.

C. To promote vasodilation and increase blood vessel permeability.

D. To inhibit phagocytosis.

8. In the context of infection, what does 'opportunistic' mean?

A. An infection that is easily treated with antibiotics.

B. An infection that only occurs in individuals with a weakened immune system.

C. An infection that is beneficial to the host.

D. An infection that is highly contagious and spreads rapidly.

9. What is sepsis?

A. A localized infection.

B. An allergic reaction.

C. A life-threatening condition caused by the body's overwhelming response to an infection.

D. An autoimmune disease.

10. Allergies are primarily mediated by which type of antibody?

A. IgG

B. IgM

C. IgE

D. IgA

11. Passive immunity is characterized by:

A. Long-lasting protection.

B. Development of immunological memory.

C. Immediate but temporary protection.

D. Production of antibodies by the individual's own immune system.

12. Which of the following is an example of a pathogen?

A. Pollen

B. Dust mites

C. Bacteria

D. Sunlight

13. Which of the following is NOT a function of antibodies?

A. Opsonization of pathogens to enhance phagocytosis.

B. Neutralization of toxins and viruses.

C. Directly killing infected cells.

D. Activation of the complement system.

14. Which of the following is NOT a function of the lymphatic system in immunity?

A. Filtering lymph to remove pathogens and cellular debris.

B. Transporting oxygen to tissues.

C. Housing immune cells, such as lymphocytes.

D. Draining excess fluid from tissues.

15. What is the function of cytotoxic T cells (CD8+ T cells)?

A. Producing antibodies.

B. Activating B cells.

C. Killing infected or cancerous cells.

D. Suppressing the immune response.

16. Antibodies are produced by which type of immune cells?

A. T lymphocytes

B. B lymphocytes

C. Natural killer cells

D. Mast cells

17. Which type of infection is caused by fungi?

A. Bacterial infection

B. Viral infection

C. Mycosis

D. Protozoan infection

18. Helper T cells (CD4+ T cells) play a crucial role in immunity by:

A. Directly killing pathogens.

B. Producing antibodies themselves.

C. Releasing cytokines to activate other immune cells, including B cells and cytotoxic T cells.

D. Mediating allergic reactions.

19. Which of the following cell types is part of the innate immune system?

A. B lymphocytes

B. T lymphocytes

C. Natural killer (NK) cells

D. Plasma cells

20. What is the function of memory cells in adaptive immunity?

A. To immediately kill pathogens upon first exposure.

B. To initiate the innate immune response.

C. To provide a faster and stronger response upon re-exposure to the same pathogen.

D. To produce antibodies during the initial infection only.

21. What is meant by 'herd immunity'?

A. Immunity acquired through natural infection only.

B. Immunity present only in animals, not humans.

C. Protection of unvaccinated individuals when a large percentage of the population is vaccinated.

D. Immunity that lasts for a lifetime.

22. Which of the following is an example of active immunity?

A. Antibodies passed from mother to baby through breast milk.

B. Antibodies received through an antiserum injection.

C. Immunity developed after recovering from chickenpox.

D. Protection provided by monoclonal antibodies.

23. What is the role of phagocytes in the immune response?

A. Producing antibodies to neutralize pathogens.

B. Killing virus-infected cells.

C. Engulfing and destroying pathogens and cellular debris.

D. Activating the complement system.

24. Which of the following is NOT a cardinal sign of inflammation?

A. Redness

B. Swelling

C. Pain

D. Numbness

25. Which of the following describes an autoimmune disease?

A. The immune system overreacts to harmless substances like pollen.

B. The immune system fails to recognize and attack pathogens.

C. The immune system attacks the body's own tissues and cells.

D. The immune system is suppressed, making the body vulnerable to infections.

26. Innate immunity, also known as natural immunity, is characterized by which of the following features?

A. Highly specific response to each pathogen.

B. Slow response, developing over weeks.

C. Memory response upon re-exposure to the same pathogen.

D. Rapid and non-specific response to pathogens.

27. What is the 'cytokine storm' often associated with severe infections?

A. A decreased production of cytokines leading to immune suppression.

B. A balanced and controlled release of cytokines during infection.

C. An excessive and uncontrolled release of pro-inflammatory cytokines, leading to tissue damage.

D. The normal inflammatory response that resolves infection effectively.

28. Which type of cells are primarily responsible for cell-mediated immunity?

A. B lymphocytes

B. Neutrophils

C. T lymphocytes

D. Macrophages

29. What is the mechanism of action of antiviral drugs?

A. To kill bacteria.

B. To inhibit viral replication inside host cells.

C. To stimulate the immune system to attack bacteria.

D. To block fungal growth.

30. Vaccination primarily works by stimulating which branch of the immune system?

A. Innate immunity

B. Adaptive immunity

C. Inflammatory response

D. Complement system