Q.1 Which of the following is the primary function of the lymphatic system?
Transport oxygen
Maintain blood pressure
Return interstitial fluid to blood
Produce red blood cells
Explanation - The lymphatic system collects excess fluid from tissues and returns it to the bloodstream, preventing edema.
Correct answer is: Return interstitial fluid to blood
Q.2 Which organ is the site of T-lymphocyte maturation?
Bone marrow
Thymus
Spleen
Lymph nodes
Explanation - T cells mature in the thymus, where they learn to distinguish self from non-self.
Correct answer is: Thymus
Q.3 Which lymphatic organ filters blood rather than lymph?
Thymus
Lymph nodes
Spleen
Tonsils
Explanation - The spleen filters blood, removes old red blood cells, and helps mount an immune response.
Correct answer is: Spleen
Q.4 Which of the following is NOT part of the lymphatic system?
Thymus
Liver
Spleen
Lymph nodes
Explanation - The liver is part of the digestive system, not the lymphatic system.
Correct answer is: Liver
Q.5 Which type of immunity is acquired after vaccination?
Innate immunity
Passive immunity
Active immunity
Nonspecific immunity
Explanation - Vaccination stimulates the body's own immune system to produce antibodies, providing active immunity.
Correct answer is: Active immunity
Q.6 Which lymphoid tissue is located in the pharynx and helps trap pathogens from food or air?
Peyer's patches
Tonsils
Thymus
Appendix
Explanation - Tonsils are clusters of lymphatic tissue in the pharynx that protect against inhaled or ingested pathogens.
Correct answer is: Tonsils
Q.7 Which cells produce antibodies?
Helper T cells
Plasma cells
Macrophages
Cytotoxic T cells
Explanation - Plasma cells are differentiated B cells that secrete large amounts of antibodies.
Correct answer is: Plasma cells
Q.8 What is lymph primarily composed of?
Red blood cells
Water and proteins
Platelets
Digestive enzymes
Explanation - Lymph is mainly water, proteins, lipids, and immune cells drained from interstitial fluid.
Correct answer is: Water and proteins
Q.9 Which structure prevents backflow of lymph?
Smooth muscle
Valves
Cilia
Capillaries
Explanation - Lymph vessels contain valves that ensure unidirectional flow toward the thoracic ducts.
Correct answer is: Valves
Q.10 Which of the following is part of the body's first line of defense?
Skin
B cells
T cells
Macrophages
Explanation - The skin is a physical barrier that prevents pathogens from entering the body.
Correct answer is: Skin
Q.11 Which antibody is the most abundant in the bloodstream?
IgM
IgA
IgG
IgE
Explanation - IgG is the most abundant antibody in circulation and provides long-term protection.
Correct answer is: IgG
Q.12 Which immune cells directly destroy virus-infected cells?
Helper T cells
Cytotoxic T cells
Plasma cells
Neutrophils
Explanation - Cytotoxic T cells kill infected or abnormal cells by releasing perforins and granzymes.
Correct answer is: Cytotoxic T cells
Q.13 Which duct drains lymph from most of the body into the bloodstream?
Right lymphatic duct
Thoracic duct
Subclavian vein
Aortic duct
Explanation - The thoracic duct drains lymph from the lower body and left side into the left subclavian vein.
Correct answer is: Thoracic duct
Q.14 Which immune response is immediate and non-specific?
Adaptive immunity
Innate immunity
Humoral immunity
Cell-mediated immunity
Explanation - Innate immunity provides immediate defense without needing prior exposure to pathogens.
Correct answer is: Innate immunity
Q.15 What is the role of lymph nodes?
Produce red blood cells
Filter lymph
Store bile
Secrete hormones
Explanation - Lymph nodes filter lymph and house immune cells that respond to pathogens.
Correct answer is: Filter lymph
Q.16 Which lymphatic organ is most active in children but shrinks with age?
Spleen
Appendix
Thymus
Tonsils
Explanation - The thymus is large and active in children, but it shrinks after puberty.
Correct answer is: Thymus
Q.17 Which immune cells are the first responders to bacterial infection?
Neutrophils
Basophils
Eosinophils
Plasma cells
Explanation - Neutrophils are fast-acting white blood cells that quickly attack bacteria.
Correct answer is: Neutrophils
Q.18 Which of the following is a lymphatic organ located in the abdomen?
Spleen
Thymus
Tonsils
Thyroid
Explanation - The spleen is located in the upper left abdomen and filters blood.
Correct answer is: Spleen
Q.19 Which type of immunity is passed from mother to baby through breast milk?
Innate immunity
Active immunity
Passive immunity
Cell-mediated immunity
Explanation - Breast milk contains maternal antibodies that provide passive immunity to the infant.
Correct answer is: Passive immunity
Q.20 Which lymphatic structure absorbs dietary fats in the small intestine?
Peyer's patches
Lacteals
Appendix
Tonsils
Explanation - Lacteals are specialized lymphatic vessels in the villi of the small intestine that absorb fats.
Correct answer is: Lacteals
Q.21 Which cell type presents antigens to activate T cells?
B cells
Macrophages
Neutrophils
Erythrocytes
Explanation - Macrophages process antigens and present them on their surface to activate T cells.
Correct answer is: Macrophages
Q.22 Which immune system disorder involves the body attacking its own tissues?
Allergy
Immunodeficiency
Autoimmune disease
Cancer
Explanation - In autoimmune diseases, the immune system mistakenly targets self-antigens as foreign.
Correct answer is: Autoimmune disease
Q.23 Which lymphatic tissue protects the small intestine from bacterial invasion?
Lacteals
Peyer's patches
Thymus
Appendix
Explanation - Peyer's patches are lymphoid nodules in the ileum that monitor gut bacteria.
Correct answer is: Peyer's patches
Q.24 What is the main role of natural killer (NK) cells?
Produce antibodies
Attack parasites
Destroy virus-infected and tumor cells
Activate B cells
Explanation - NK cells recognize and kill abnormal cells without prior activation.
Correct answer is: Destroy virus-infected and tumor cells
Q.25 Which immune response involves antibodies circulating in the blood?
Cell-mediated immunity
Innate immunity
Humoral immunity
Inflammation
Explanation - Humoral immunity involves B cells and antibodies targeting pathogens in body fluids.
Correct answer is: Humoral immunity