50 Human Blood MCQs with Answers and Detailed Explanations-
Are you preparing for a biology exam or looking to test your knowledge of human blood? In this blog, we’ve compiled 50 multiple-choice questions (MCQs) on human blood, complete with detailed answers and explanations. Whether you’re a student, teacher, or medical professional, these MCQs will help you understand the components, functions, and disorders related to human blood. Let’s dive in!
Introduction to Human Blood
Human blood is a vital fluid that performs numerous functions, including transporting oxygen, fighting infections, and maintaining homeostasis. In this blog, we’ve compiled 50 multiple-choice questions (MCQs) to help you test and expand your knowledge of human blood.
Key Functions of Blood Components:
- Red Blood Cells: Transport oxygen
- White Blood Cells: Fight infections
- Platelets: Clot blood
- Plasma: Maintains fluid balance
Topics covered -
"Human blood MCQs"
"Blood-related multiple-choice questions"
"Functions of blood components"
"Blood disorders and their explanations"
"Blood types and their significance"
"Blood cells and their roles"
MCQs on Red Blood Cells (RBCs)
Basics of Red Blood Cells
1. What is the primary function of red blood cells (RBCs)?
a) Fight infections
b) Transport oxygen
c) Clot blood
d) Produce antibodies
Answer: b) Transport oxygen
Explanation: Red blood cells contain hemoglobin, a protein that binds to oxygen and transports it from the lungs to the rest of the body.
2. Which component of blood is responsible for clotting?
a) Plasma
b) Platelets
c) White blood cells
d) Red blood cells
Answer: b) Platelets
Explanation: Platelets (thrombocytes) are small cell fragments that help form blood clots to stop bleeding.
3. What is the liquid portion of blood called?
a) Serum
b) Plasma
c) Lymph
d) Hemoglobin
Answer: b) Plasma
Explanation: Plasma is the liquid component of blood, making up about 55% of its volume. It contains water, proteins, hormones, and waste products.
4. Which blood type is considered the universal donor?
a) A
b) B
c) AB
d) O
Answer: d) O
Explanation: Blood type O negative is the universal donor because it lacks A, B, and Rh antigens, reducing the risk of rejection during transfusions.
5. Which blood type is considered the universal recipient?
a) A
b) B
c) AB
d) O
Answer: c) AB
Explanation: Blood type AB positive is the universal recipient because it has both A and B antigens and the Rh factor, allowing it to receive blood from any type.
MCQs on White Blood Cells (WBCs)
Basics of White Blood Cells
6. What is the normal pH range of human blood?
a) 6.8–7.0
b) 7.0–7.2
c) 7.35–7.45
d) 7.5–7.8
blood-ph-balance-normal-range-ultra-HD-4K.png
Answer: c) 7.35–7.45
Explanation: Blood is slightly alkaline, with a normal pH range of 7.35 to 7.45. Deviations from this range can indicate health issues.
7. Which white blood cells are primarily involved in fighting bacterial infections?
a) Lymphocytes
b) Monocytes
c) Neutrophils
d) Eosinophils
Answer: c) Neutrophils
Explanation: Neutrophils are the most abundant type of white blood cells and are the first responders to bacterial infections.
8. What is the lifespan of a red blood cell?
a) 30 days
b) 60 days
c) 120 days
d) 1 year
Answer: c) 120 days
Explanation: Red blood cells have a lifespan of about 120 days before they are broken down and recycled in the spleen and liver.
9. Which hormone stimulates the production of red blood cells?
a) Insulin
b) Thyroxine
c) Erythropoietin
d) Adrenaline
Answer: c) Erythropoietin
Explanation: Erythropoietin is a hormone produced by the kidneys that stimulates the bone marrow to produce red blood cells.
10. What is the main function of white blood cells (WBCs)?
a) Transport oxygen
b) Fight infections
c) Clot blood
d) Regulate blood pressure
Answer: b) Fight infections
Explanation: White blood cells are part of the immune system and defend the body against infections and foreign invaders.
11. Which blood cells are biconcave in shape?
a) Platelets
b) Red blood cells
c) White blood cells
d) Plasma cells
Answer: b) Red blood cells
Explanation: Red blood cells have a unique biconcave shape, which increases their surface area for efficient oxygen transport.
12. What is anemia?
a) Excess of red blood cells
b) Deficiency of white blood cells
c) Deficiency of red blood cells or hemoglobin
d) Excess of platelets
Answer: c) Deficiency of red blood cells or hemoglobin
Explanation: Anemia is a condition characterized by a lack of healthy red blood cells or hemoglobin, leading to reduced oxygen transport.
13. Which vitamin is essential for blood clotting?
a) Vitamin A
b) Vitamin C
c) Vitamin D
d) Vitamin K
Answer: d) Vitamin K
Explanation: Vitamin K is essential for the synthesis of clotting factors in the liver, which are necessary for blood coagulation.
14. What is the function of hemoglobin?
a) Transport oxygen
b) Fight infections
c) Clot blood
d) Regulate blood sugar
Answer: a) Transport oxygen
Explanation: Hemoglobin is a protein in red blood cells that binds to oxygen and carries it to tissues throughout the body.
15. What is the normal range of white blood cells (WBCs) per microliter of blood?
a) 1,000–3,000
b) 4,000–11,000
c) 12,000–15,000
d) 20,000–30,000
Answer: b) 4,000–11,000
Explanation: The normal range of white blood cells in adults is typically between 4,000 and 11,000 per microliter of blood.
16. Which blood disorder is characterized by abnormal hemoglobin?
a) Anemia
b) Leukemia
c) Sickle cell anemia
d) Hemophilia
Answer: c) Sickle cell anemia
Explanation: Sickle cell anemia is a genetic disorder where red blood cells have abnormal hemoglobin, causing them to become sickle-shaped and less efficient at carrying oxygen.
17. What is the role of fibrin in blood clotting?
a) It forms a mesh to trap platelets
b) It dissolves blood clots
c) It transports oxygen
d) It fights infections
Answer: a) It forms a mesh to trap platelets
Explanation: Fibrin is a protein that forms a mesh-like structure during blood clotting, trapping platelets and forming a stable clot.
18. Which organ produces most of the plasma proteins?
a) Liver
b) Spleen
c) Kidneys
d) Bone marrow
Answer: a) Liver
Explanation: The liver synthesizes most of the plasma proteins, including albumin, clotting factors, and globulins.
19. What is the function of albumin in blood plasma?
a) Transport oxygen
b) Maintain osmotic pressure
c) Fight infections
d) Clot blood
Answer: b) Maintain osmotic pressure
Explanation: Albumin is a plasma protein that helps maintain osmotic pressure, preventing fluid from leaking out of blood vessels.
20. Which blood cells are involved in allergic reactions?
a) Neutrophils
b) Eosinophils
c) Lymphocytes
d) Monocytes
Answer: b) Eosinophils
Explanation: Eosinophils are white blood cells that play a key role in combating parasitic infections and mediating allergic reactions.
21. What is the Rh factor?
a) A type of white blood cell
b) A protein on the surface of red blood cells
c) A clotting factor
d) A hormone
Answer: b) A protein on the surface of red blood cells
Explanation: The Rh factor is an antigen present on the surface of red blood cells. People with the antigen are Rh-positive, while those without it are Rh-negative.
22. What is hemophilia?
a) A deficiency of red blood cells
b) A deficiency of white blood cells
c) A disorder of blood clotting
d) A disorder of blood pressure regulation
Answer: c) A disorder of blood clotting
Explanation: Hemophilia is a genetic disorder where the blood does not clot properly due to a deficiency in clotting factors.
23. Which blood cells are responsible for antibody production?
a) Neutrophils
b) Lymphocytes
c) Monocytes
d) Eosinophils
Answer: b) Lymphocytes
Explanation: Lymphocytes, particularly B cells, are responsible for producing antibodies that target specific pathogens.
24. What is the normal hematocrit level for adult males?
a) 20–30%
b) 30–40%
c) 40–50%
d) 50–60%
Answer: c) 40–50%
Explanation: Hematocrit measures the percentage of red blood cells in blood. For adult males, the normal range is 40–50%.
25. What is the function of the spleen in relation to blood?
a) Produce red blood cells
b) Filter and store blood
c) Produce platelets
d) Regulate blood pressure
Answer: b) Filter and store blood
Explanation: The spleen filters blood, removes old or damaged red blood cells, and stores platelets and white blood cells.
26. Which blood cells are involved in long-term immunity?
a) Neutrophils
b) Lymphocytes
c) Monocytes
d) Eosinophils
Answer: b) Lymphocytes
Explanation: Lymphocytes, including T cells and B cells, are responsible for long-term immunity by remembering and targeting specific pathogens.
27. What is the primary function of monocytes?
a) Phagocytosis
b) Antibody production
c) Blood clotting
d) Oxygen transport
Answer: a) Phagocytosis
Explanation: Monocytes are large white blood cells that engulf and digest pathogens and cellular debris through phagocytosis.
28. What is the normal range of platelets per microliter of blood?
a) 10,000–50,000
b) 100,000–150,000
c) 150,000–450,000
d) 500,000–1,000,000
Answer: c) 150,000–450,000
Explanation: The normal platelet count ranges from 150,000 to 450,000 per microliter of blood.
29. What is the role of iron in blood?
a) It helps in blood clotting
b) It is a component of hemoglobin
c) It fights infections
d) It regulates blood pressure
Answer: b) It is a component of hemoglobin
Explanation: Iron is a key component of hemoglobin, enabling it to bind and transport oxygen.
30. Which blood cells are involved in parasitic infections?
a) Neutrophils
b) Eosinophils
c) Lymphocytes
d) Monocytes
Answer: b) Eosinophils
Explanation: Eosinophils are specialized white blood cells that combat parasitic infections and are also involved in allergic reactions.
31. What is the function of basophils?
a) Phagocytosis
b) Release histamine
c) Produce antibodies
d) Transport oxygen
Answer: b) Release histamine
Explanation: Basophils release histamine and other chemicals during allergic reactions and inflammation.
32. What is the normal hemoglobin level for adult females?
a) 10–12 g/dL
b) 12–14 g/dL
c) 14–16 g/dL
d) 16–18 g/dL
Answer: b) 12–14 g/dL
Explanation: The normal hemoglobin level for adult females is typically between 12 and 14 grams per deciliter (g/dL).
33. What is the role of the bone marrow in blood production?
a) It filters blood
b) It produces blood cells
c) It stores blood
d) It regulates blood pressure
Answer: b) It produces blood cells
Explanation: Bone marrow is the primary site of hematopoiesis, the production of all types of blood cells.
34. What is leukopenia?
a) Excess of white blood cells
b) Deficiency of white blood cells
c) Excess of red blood cells
d) Deficiency of platelets
Answer: b) Deficiency of white blood cells
Explanation: Leukopenia is a condition characterized by a low white blood cell count, increasing the risk of infections.
35. What is the function of globulins in blood plasma?
a) Transport oxygen
b) Maintain osmotic pressure
c) Fight infections
d) Clot blood
Answer: c) Fight infections
Explanation: Globulins are plasma proteins that include antibodies (immunoglobulins), which play a key role in the immune response.
36. What is the role of the kidneys in blood regulation?
a) Produce red blood cells
b) Filter waste products
c) Produce platelets
d) Regulate blood sugar
Answer: b) Filter waste products
Explanation: The kidneys filter waste products from the blood and help regulate blood volume, pressure, and pH.
37. What is the normal blood volume in an adult human?
a) 2–3 liters
b) 4–6 liters
c) 7–8 liters
d) 9–10 liters
Answer: b) 4–6 liters
Explanation: The average adult has a blood volume of about 4 to 6 liters, depending on body size and composition.
38. What is the function of the lymphatic system in relation to blood?
a) Transport oxygen
b) Filter blood
c) Return interstitial fluid to the bloodstream
d) Produce red blood cells
Answer: c) Return interstitial fluid to the bloodstream
Explanation: The lymphatic system collects and returns interstitial fluid (lymph) to the bloodstream, maintaining fluid balance.
39. What is the role of calcium in blood clotting?
a) It activates clotting factors
b) It transports oxygen
c) It fights infections
d) It regulates blood pressure
Answer: a) It activates clotting factors
Explanation: Calcium ions are essential for the activation of several clotting factors in the coagulation cascade.
40. What is polycythemia?
a) Excess of red blood cells
b) Deficiency of white blood cells
c) Deficiency of platelets
d) Excess of plasma
Answer: a) Excess of red blood cells
Explanation: Polycythemia is a condition characterized by an abnormal increase in red blood cells, leading to thicker blood.
41. What is the role of the liver in blood clotting?
a) It produces clotting factors
b) It filters blood
c) It stores platelets
d) It produces red blood cells
Answer: a) It produces clotting factors
Explanation: The liver synthesizes most of the clotting factors required for blood coagulation.
42. What is the function of the thymus in relation to blood?
a) Produce red blood cells
b) Mature T lymphocytes
c) Filter blood
d) Store platelets
Answer: b) Mature T lymphocytes
Explanation: The thymus is an organ where T lymphocytes mature and become functional for the immune system.
43. What is the role of carbonic anhydrase in red blood cells?
a) Transport oxygen
b) Convert carbon dioxide to bicarbonate
c) Clot blood
d) Fight infections
Answer: b) Convert carbon dioxide to bicarbonate
Explanation: Carbonic anhydrase is an enzyme in red blood cells that converts carbon dioxide into bicarbonate for transport in the blood.
44. What is the normal range of red blood cells (RBCs) per microliter of blood in males?
a) 3–4 million
b) 4–5 million
c) 5–6 million
d) 6–7 million
Answer: c) 5–6 million
Explanation: The normal range of red blood cells in adult males is typically 5 to 6 million per microliter of blood.
45. What is the role of the complement system in blood?
a) Transport oxygen
b) Enhance immune response
c) Clot blood
d) Regulate blood pressure
Answer: b) Enhance immune response
Explanation: The complement system is a group of proteins that enhance the immune response by attacking pathogens and promoting inflammation.
46. What is the function of transferrin in blood?
a) Transport oxygen
b) Transport iron
c) Clot blood
d) Fight infections
Answer: b) Transport iron
Explanation: Transferrin is a plasma protein that binds and transports iron in the blood.
47. What is the role of the sinoatrial (SA) node in blood circulation?
a) Filter blood
b) Regulate blood pressure
c) Act as the heart's pacemaker
d) Produce red blood cells
Answer: c) Act as the heart's pacemaker
Explanation: The SA node generates electrical impulses that regulate the heartbeat, ensuring proper blood circulation.
48. What is the function of the pulmonary circulation system?
a) Transport oxygenated blood to the body
b) Transport deoxygenated blood to the lungs
c) Filter blood
d) Store blood
Answer: b) Transport deoxygenated blood to the lungs
Explanation: The pulmonary circulation system carries deoxygenated blood from the heart to the lungs for oxygenation.
49. What is the role of the aorta in blood circulation?
a) Carry deoxygenated blood to the lungs
b) Carry oxygenated blood to the body
c) Filter blood
d) Store blood
Answer: b) Carry oxygenated blood to the body
Explanation: The aorta is the largest artery in the body and carries oxygenated blood from the heart to the rest of the body.
50. What is the function of the coronary arteries?
a) Supply blood to the heart muscle
b) Carry blood to the lungs
c) Filter blood
d) Store blood
Answer: a) Supply blood to the heart muscle
Explanation: The coronary arteries supply oxygen-rich blood to the heart muscle, ensuring its proper function.
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