Q21. Blood plasma contains:
a) Red and white blood cells only
b) Platelets and white blood cells only
c) Red blood cells and platelets only
d) Water, proteins, and dissolved substances
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Correct Answer: d) Water, proteins, and dissolved substances
Explanation: Blood plasma is a yellowish liquid component of blood that holds the blood cells in whole blood in suspension. It is about 92% water and contains proteins, glucose, clotting factors, mineral ions, hormones, and carbon dioxide.
Q22. Which type of blood cells are primarily responsible for oxygen transport?
a) Erythrocytes
b) Leukocytes
c) Thrombocytes
d) Neutrophils
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Correct Answer: a) Erythrocytes
Explanation: Erythrocytes, or red blood cells, are primarily responsible for oxygen transport. They contain hemoglobin, an iron-containing biomolecule that can bind oxygen and carry it from the lungs to the rest of the body.
Q23. The main function of leukocytes or white blood cells is:
a) Clotting blood
b) Transporting nutrients
c) Fighting infections
d) Carrying oxygen
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Correct Answer: c) Fighting infections
Explanation: Leukocytes, or white blood cells, are an essential part of the immune system. Their main function is to fight infections and provide defense against both infectious disease and foreign materials.
Q24. Hemoglobin is:
a) A type of white blood cell
b) A clotting factor in blood
c) An oxygen-carrying protein in red blood cells
d) A plasma protein that maintains osmotic pressure
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Correct Answer: c) An oxygen-carrying protein in red blood cells
Explanation: Hemoglobin is a protein in red blood cells that carries oxygen. Each hemoglobin molecule can bind up to four oxygen molecules and is responsible for the red color of the cells.
Q25. A person with blood type O can receive red blood cells from a donor of type:
a) Only O
b) A, B, AB, and O
c) Only A and O
d) Only B and O
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Correct Answer: a) Only O
Explanation: People with blood type O can receive red blood cells only from donors with type O blood. This is because type O blood does not have A or B antigens on the red blood cells, and therefore will not be rejected by the recipient’s immune system.
Q26. Which of the following is a function of platelets in blood?
a) Fighting infection
b) Transporting gases
c) Blood clotting
d) Producing antibodies
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Correct Answer: c) Blood clotting
Explanation: Platelets, or thrombocytes, play a key role in blood clotting. They gather at the site of a blood vessel injury, adhere to the vessel’s wall, and form a plug that seals small breaks.
Q27. The liquid part of blood, without cells and clotting factors, is known as:
a) Plasma
b) Serum
c) Lymph
d) Interstitial fluid
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Correct Answer: b) Serum
Explanation: Serum is the liquid part of the blood that remains after blood has clotted and the clotting factors have been removed. This is distinct from plasma, which is the liquid part of blood with clotting factors included.
Q28. Which condition is characterized by a deficiency in the quantity or quality of red blood cells?
a) Anemia
b) Leukemia
c) Thrombocytopenia
d) Hemophilia
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Correct Answer: a) Anemia
Explanation: Anemia is a condition characterized by a deficiency in the number or quality of red blood cells, or in the amount of hemoglobin they contain. This results in decreased oxygen transport capacity of the blood.
Q29. The blood cells that are primarily involved in antibody production are:
a) Red blood cells
b) Monocytes
c) Lymphocytes
d) Eosinophils
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Correct Answer: c) Lymphocytes
Explanation: Lymphocytes, a type of white blood cell, are significantly involved in the immune response, including antibody production. B lymphocytes, in particular, are responsible for producing antibodies that help in fighting infections.
Q30. Which is the most abundant type of white blood cell in human blood?
a) Eosinophils
b) Basophils
c) Neutrophils
d) Lymphocytes
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Correct Answer: c) Neutrophils
Explanation: Neutrophils are the most abundant type of white blood cells in human blood, representing about 50-70% of all white blood cells. They play a key role in the innate immune system, responding quickly to infections, especially bacterial.