Free Blood and Immunity MCQs with Answers

• A. Water
• B. Albumin
• C. Fibrinogen
• D. Electrolytes

Explanation: Water makes up most of plasma and provides the medium for transporting cells, nutrients, hormones and waste products.

• A. 10 days
• B. 30 days
• C. 120 days
• D. 365 days

Explanation: A normal red blood cell has an average lifespan of about 120 days before it is removed mainly by the spleen and liver.

• A. Helper T cell
• B. Cytotoxic T cell
• C. Memory B cell
• D. Plasma cell

Explanation: Cytotoxic T cells recognize and destroy infected, cancerous or otherwise abnormal cells.

• A. Anti-A only
• B. Anti-B only
• C. Anti-A and anti-B
• D. No ABO antibodies

Explanation: Group O plasma normally contains both anti-A and anti-B antibodies because the red cells have neither A nor B antigen.

• A. A antigen
• B. B antigen
• C. D antigen
• D. H antigen

Explanation: Rh-positive blood has the D antigen on the red blood cell surface. A and B antigens determine the ABO group, whereas H antigen is not the…

• A. Slow the transfusion rate
• B. Stop the transfusion immediately
• C. Give the next prescribed unit
• D. Flush the line with dextrose solution

Explanation: These findings may indicate an acute haemolytic transfusion reaction, so the transfusion must be stopped immediately to prevent further…

• A. They digest bacteria during the first response
• B. They produce clotting factors in plasma
• C. They allow a faster response to a later exposure
• D. They prevent all microorganisms entering the skin

Explanation: Memory B and T lymphocytes remain after an initial specific immune response and help the body respond more rapidly during later exposure…

• A. Innate immunity
• B. Passive immunity
• C. Humoral memory
• D. Acquired antibody transfer

Explanation: Skin and mucous membranes provide nonspecific barriers that act before exposure to a particular antigen, so they are components of innate…

• A. It develops slowly and lasts lifelong
• B. It uses the patient's memory cells
• C. It provides immediate temporary protection
• D. It requires the patient to produce new antibodies first

Explanation: Administered immunoglobulin supplies antibodies directly, giving passive immunity that acts quickly but usually provides temporary…

• A. Neutralisation
• B. Phagocytosis
• C. Haemopoiesis
• D. Chemotaxis

Explanation: Neutralisation occurs when an antibody blocks a toxin or microorganism from attaching to or entering host cells.

• A. The percentage of blood made up of red blood cells
• B. The percentage of plasma made up of clotting factors
• C. The amount of oxygen dissolved in the plasma
• D. The number of white blood cells in a blood sample

Explanation: Haematocrit is the proportion of whole blood occupied by red blood cells.

• A. Adhesion to exposed damaged tissue
• B. Production of antibodies against bacteria
• C. Destruction of aged red blood cells
• D. Release of oxygen into body tissues

Explanation: Platelets adhere to exposed structures at the injured vessel wall and help form the initial platelet plug.

• A. Macrophage
• B. Plasma cell
• C. Eosinophil
• D. Mast cell

Explanation: Monocytes develop into macrophages after entering tissues, where they phagocytose organisms and cellular debris.

• A. They are part of innate immunity and kill some abnormal cells
• B. They produce antibodies after exposure to a vaccine
• C. They form platelets in the bone marrow
• D. They release clotting factors into damaged vessels

Explanation: Natural killer cells provide rapid innate defence by destroying some virus-infected and tumour cells without prior specific sensitisation.

• A. Immunoglobulin M
• B. Immunoglobulin A
• C. Immunoglobulin E
• D. Immunoglobulin G

Explanation: Immunoglobulin M is generally the first major antibody released during a primary response.

• A. Secretory immunoglobulin A
• B. Immunoglobulin M in red cells
• C. Immunoglobulin E in platelets
• D. Immunoglobulin G in neutrophils

Explanation: Secretory immunoglobulin A in breast milk provides natural passive protection, especially across the infant's gastrointestinal and…

• A. Factor VIII
• B. Factor II
• C. Factor V
• D. Factor XII

Explanation: Haemophilia A results from deficiency of factor VIII, an intrinsic pathway clotting factor.

• A. To prevent the mother from forming anti-D antibodies
• B. To increase the fetal platelet count
• C. To stimulate the mother to make Rh-positive cells
• D. To destroy all antibodies in the maternal plasma

Explanation: Anti-D immunoglobulin removes or neutralises fetal Rh-positive red cells that enter the mother's circulation, reducing maternal…

• A. It responds specifically to particular antigens
• B. It is present as an intact skin barrier
• C. It acts immediately against many unrelated threats
• D. It includes protective secretions on mucous membranes

Explanation: Adaptive immunity recognises particular antigens and develops responses involving specific lymphocytes.

• A. Petechiae and bleeding from mucous membranes
• B. Deep muscle bleeding with joint swelling
• C. Yellow skin from increased bilirubin
• D. Severe cyanosis from low oxygen saturation

Explanation: Platelets are essential for the initial platelet plug, so thrombocytopenia commonly causes petechiae and mucosal bleeding.