MDCAT WITH UMAR SANI Daily Practice Test CHAPTER:IMMUNITY 1. Which cells are primarily responsible for producing antibodies? (2016) a) Macrophages b) T cells c) B cells d) Neutrophils 2. What is the main function of helper T cells in the immune response? (2017) a) Phagocytosis b) Antibody production c) Activating other immune cells d) Destroying infected cells 3. Which of the following is a component of the innate immune system? (2018) a) Antibodies b) Cytotoxic T cells c) Skin d) Memory B cells 4. What is the role of the thymus in the immune system? (2019) a) Producing red blood cells b) Maturation of T cells c) Filtering lymph d) Producing antibodies 5. Which type of immunity is provided by a vaccine? (2020) a) Natural active immunity b) Artificial active immunity c) Natural passive immunity d) Artificial passive immunity 6. Which immunoglobulin is most abundant in the bloodstream? (2021) a) IgA b) IgM c) IgG d) IgE 7. What is the function of cytotoxic T cells? (2016) a) Produce antibodies b) Help other immune cells c) Kill infected cells d) Activate B cells 8. Which of the following is an autoimmune disease? (2017) a) Tuberculosis b) Rheumatoid arthritis c) Malaria d) Measles 9. What type of cells are memory cells derived from? (2018) a) T cells only b) B cells only c) Both T cells and B cells d) Macrophages 10. Which pathway involves the complement system in immune responses? (2019) a) Classical pathway b) Alternative pathway c) Lectin pathway d) All of the above 11. What triggers the inflammatory response in the immune system? (2020) a) Antibodies b) Histamines c) T cells d) Cytokines 12. Which organ is the primary site for the production of immune cells? (2021) a) Thymus b) Bone marrow c) Spleen d) Lymph nodes 13. Which part of the immune system is responsible for recognizing antigens? (2016) a) Phagocytes b) Antibodies c) T cell receptors d) Complement proteins 14. What is the primary role of natural killer (NK) cells? (2017) a) Phagocytosis b) Antigen presentation c) Destroying virus-infected cells d) Producing antibodies 15. Which cells act as antigen-presenting cells (APCs)? (2018) a) T cells b) B cells c) Dendritic cells d) Neutrophils 16. What is the role of interferons in the immune system? (2019) a) Stimulate B cell activation b) Inhibit viral replication c) Enhance phagocytosis d) Destroy infected cells 17. Which immune response is characterized by the production of antibodies? (2020) a) Cell-mediated immunity b) Humoral immunity c) Innate immunity d) Passive immunity 18. Which cells are involved in the cell-mediated immune response? (2021) a) B cells b) Plasma cells c) T cells d) Macrophages 19. Which molecule acts as a signal for the immune system to respond? (2016) a) Antigen b) Histamine c) Cytokine d) Antibody 20. What is the function of regulatory T cells in the immune system? (2017) a) Suppress immune responses b) Activate B cells c) Produce antibodies d) Destroy pathogens 21. Which immunoglobulin is associated with allergic reactions? (2018) a) IgA b) IgM c) IgG d) IgE 22. Which cells are the first responders to a site of infection? (2019) a) Neutrophils b) Macrophages c) B cells d) T cells 23. Which type of hypersensitivity involves antibodies and is immediate? (2020) a) Type I b) Type II c) Type III d) Type IV 24. Which part of the immune system is primarily responsible for fighting bacterial infections? (2021) a) T cells b) B cells c) Macrophages d) Natural killer cells 25. What is the purpose of the major histocompatibility complex (MHC) in immunity? (2016) a) Produce antibodies b) Present antigens c) Destroy pathogens d) Activate T cells 26. Which organ stores and filters blood as part of the immune system? (2017) a) Thymus b) Spleen c) Liver d) Lymph nodes 27. What is the role of plasma cells in the immune system? (2018) a) Produce cytokines b) Present antigens c) Produce antibodies d) Attack infected cells 28. Which type of immunity involves the transfer of antibodies from mother to child? (2019) a) Natural active immunity b) Artificial active immunity c) Natural passive immunity d) Artificial passive immunity 29. Which cells are primarily involved in the allergic response? (2020) a) T cells b) B cells c) Mast cells d) Neutrophils 30. Which enzyme is present in tears and saliva that helps destroy bacteria? (2021) a) Amylase b) Lysozyme c) Protease d) Lipase 𝐏𝐀𝐊𝐈𝐒𝐓𝐀𝐍 𝐍𝐎 01 𝐌𝐄𝐃𝐈𝐂𝐀𝐋 𝐂𝐇𝐀𝐍𝐍𝐄𝐋 𝐅𝐎𝐑 𝐄𝐍𝐓𝐑𝐘 𝐓𝐄𝐒𝐓 𝐏𝐑𝐄𝐏𝐀𝐑𝐀𝐓𝐈𝐎𝐍 𝐌𝐄𝐃𝐈𝐂𝐀𝐋 𝐖𝐈𝐓𝐇 𝐔𝐌𝐀𝐑 𝐒𝐀𝐍𝐈 https://whatsapp.com/chan nel/0029VaDayrjFMqrQqJ9P Te0h ANSWERS WITH EXPLANATION 1. c) B cells Explanation: B cells are a type of white blood cell that, when activated, differentiate into plasma cells that produce antibodies specific to antigens. 2. c) Activating other immune cells Explanation: Helper T cells (CD4+ T cells) play a critical role in the immune response by secreting cytokines that activate and coordinate the activity of other immune cells like B cells and cytotoxic T cells. 3. c) Skin Explanation: The skin acts as a physical barrier and is a component of the innate immune system, providing the first line of defense against pathogens. 4. b) Maturation of T cells Explanation: The thymus is where T cells mature. Immature T cells (thymocytes) develop into functional T cells capable of recognizing specific antigens. 5. b) Artificial active immunity Explanation: Vaccines stimulate the immune system to produce antibodies and memory cells against specific pathogens, providing long-term immunity without causing the disease. 6. c) IgG Explanation: IgG is the most abundant immunoglobulin in the blood and provides the majority of antibody-based immunity against pathogens. 7. c) Kill infected cells Explanation: Cytotoxic T cells (CD8+ T cells) recognize and destroy cells infected with viruses or other intracellular pathogens by inducing apoptosis (programmed cell death). 8. b) Rheumatoid arthritis Explanation: Rheumatoid arthritis is an autoimmune disease in which the immune system mistakenly attacks the body's own tissues, particularly the joints. 9. c) Both T cells and B cells Explanation: Memory cells, which can be either memory T cells or memory B cells, are long-lived and can quickly respond to previously encountered antigens, providing faster and stronger immune responses. 10. d) All of the above Explanation: The complement system can be activated through the classical, alternative, and lectin pathways, each leading to the activation of a cascade of proteins that enhance immune responses. 11. b) Histamines Explanation: Histamines are released by mast cells and basophils during an immune response, causing vasodilation and increased permeability of blood vessels, leading to inflammation. 12. b) Bone marrow Explanation: Bone marrow is the primary site of hematopoiesis, where all blood cells, including immune cells such as lymphocytes, are produced from hematopoietic stem cells. 13. c) T cell receptors Explanation: T cell receptors (TCRs) on T cells recognize and bind to specific antigens presented by antigen-presenting cells, initiating an immune response. 14. c) Destroying virus-infected cells Explanatio: Natural killer (NK) cells are a type of lymphocyte that can recognize and destroy virus-infected cells or tumor cells without prior sensitization. 15. c) Dendritic cells Explanation: Dendritic cells are professional antigen-presenting cells that process antigens and present them to T cells, thus initiating the adaptive immune response. 16. b) Inhibit viral replication Explanation: Interferons are cytokines produced by virus-infected cells that help protect nearby cells by inhibiting viral replication and enhancing the immune response. 17. b) Humoral immunity Explanation: Humoral immunity involves B cells and the production of antibodies that circulate in the blood and lymph, targeting extracellular pathogens and toxins. 18. c) T cells Explanation: Cell-mediated immunity primarily involves T cells, which directly attack infected or cancerous cells and coordinate the overall immune response. 19. c) Cytokine Explanation: Cytokines are signaling molecules released by immune cells that regulate the intensity and duration of the immune response by communicating between cells. 20. a) Suppress immune responses Explanation: Regulatory T cells (Tregs) help maintain immune system balance by suppressing excessive immune responses and preventing autoimmune diseases. 21. d) IgE Explanation: IgE antibodies are involved in allergic reactions and bind to allergens, triggering the release of histamine and other chemicals from mast cells. 22. a) Neutrophils Explanation: Neutrophils are a type of white blood cell that quickly migrate to infection sites, where they engulf and destroy bacteria and other pathogens. 23. a) Type I Explanation: Type I hypersensitivity, or immediate hypersensitivity, is mediated by IgE antibodies and results in allergic reactions such as hay fever or anaphylaxis. 24. b) B cells Explanation: B cells produce antibodies that specifically target and neutralize bacteria, making them essential for fighting bacterial infections. 25. b) Present antigens Explanation: MHC molecules on the surface of cells present antigens to T cells, facilitating the recognition of foreign substances by the immune system. 26. b) Spleen Explanation: The spleen filters blood, removing old or damaged red blood cells and pathogens. It also plays a role in the immune response by producing lymphocytes. 27. c) Produce antibodies Explanation: Plasma cells are differentiated B cells that produce and secrete large quantities of antibodies specific to an antigen. 28. c) Natural passive immunity Explanation: Natural passive immunity occurs when a mother transfers antibodies to her child through the placenta or breast milk, providing temporary protection. 29. c) Mast cells Explanation: Mast cells release histamine and other mediators during an allergic response, causing symptoms such as itching, swelling, and redness. 30. b) Lysozyme Explanation: Lysozyme is an enzyme found in tears, saliva, and other body fluids that breaks down bacterial cell walls, providing a protective antimicrobial function. 𝐏𝐀𝐊𝐈𝐒𝐓𝐀𝐍 𝐍𝐎 01 𝐌𝐄𝐃𝐈𝐂𝐀𝐋 𝐂𝐇𝐀𝐍𝐍𝐄𝐋 𝐅𝐎𝐑 𝐄𝐍𝐓𝐑𝐘 𝐓𝐄𝐒𝐓 𝐏𝐑𝐄𝐏𝐀𝐑𝐀𝐓𝐈𝐎𝐍 𝐌𝐄𝐃𝐈𝐂𝐀𝐋 𝐖𝐈𝐓𝐇 𝐔𝐌𝐀𝐑 𝐒𝐀𝐍𝐈 https://whatsapp.com/chan nel/0029VaDayrjFMqrQqJ9P Te0h
