Q41. Which blood vessels are primarily responsible for the exchange of gases and nutrients with tissues?
a) Arteries
b) Veins
c) Capillaries
d) Venules
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Correct Answer: c) Capillaries
Explanation: Capillaries are the smallest blood vessels and are primarily responsible for the exchange of gases, nutrients, and waste products between the blood and tissues. Their thin walls allow for efficient diffusion of substances.
Q42. The clotting factor deficiency that leads to hemophilia A is:
a) Factor VIII
b) Factor IX
c) Factor X
d) Factor V
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Correct Answer: a) Factor VIII
Explanation: Hemophilia A, the most common type of hemophilia, is caused by a deficiency in clotting factor VIII. This deficiency impairs the blood clotting process, leading to prolonged bleeding after injury.
Q43. Blood type is determined by:
a) The shape of red blood cells
b) The type of plasma
c) The presence or absence of specific antigens on the red blood cells
d) The number of platelets
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Correct Answer: c) The presence or absence of specific antigens on the red blood cells
Explanation: Blood type is determined by the presence or absence of specific antigens on the surface of red blood cells. These antigens are proteins or sugars that can provoke an immune response if they are foreign to the body.
Q44. Which organ is responsible for filtering aged red blood cells from the bloodstream?
a) Liver
b) Kidneys
c) Heart
d) Spleen
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Correct Answer: d) Spleen
Explanation: The spleen is responsible for filtering aged and damaged red blood cells from the bloodstream. It also helps fight certain kinds of bacteria that cause pneumonia and meningitis.
Q45. What is polycythemia?
a) A decrease in white blood cell count
b) An increase in red blood cell count
c) A decrease in plasma volume
d) An increase in platelet count
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Correct Answer: b) An increase in red blood cell count
Explanation: Polycythemia is a condition characterized by an increased number of red blood cells in the blood. This can lead to a thickening of the blood, which can increase the risk of clotting and other complications.
Q46. What is the primary role of the protein albumin in the blood?
a) Transporting oxygen
b) Maintaining osmotic pressure
c) Clotting blood
d) Fighting infection
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Correct Answer: b) Maintaining osmotic pressure
Explanation: Albumin, a protein in the blood, plays a key role in maintaining osmotic pressure, which helps to keep fluid from leaking out of blood vessels. Albumin also transports various substances including hormones and vitamins.
Q47. What is the primary cause of anemia?
a) High blood sugar levels
b) Decreased oxygen carrying capacity of blood
c) Excess of calcium in blood
d) Overproduction of white blood cells
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Correct Answer: b) Decreased oxygen carrying capacity of blood
Explanation: Anemia is primarily caused by a decrease in the oxygen-carrying capacity of the blood, which is often due to a reduction in the number of red blood cells or hemoglobin levels. This leads to symptoms like fatigue and weakness.
Q48. Which blood cells are involved in producing antibodies?
a) Red blood cells
b) Platelets
c) Plasma cells
d) Eosinophils
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Correct Answer: c) Plasma cells
Explanation: Plasma cells, a type of white blood cell, are involved in the production of antibodies. They are derived from B lymphocytes and play a critical role in the immune response by producing antibodies specific to antigens.
Q49. The majority of carbon dioxide in the blood is transported:
a) As bicarbonate ions in plasma
b) Bound to hemoglobin
c) In the form of carbonic acid
d) As dissolved gas in red blood cells
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Correct Answer: a) As bicarbonate ions in plasma
Explanation: The majority of carbon dioxide in the blood is transported in the form of bicarbonate ions in plasma. Carbon dioxide is converted into bicarbonate ions in red blood cells, which are then transported in the plasma.
Q50. What is the primary function of neutrophils?
a) Producing antibodies
b) Transporting oxygen
c) Blood clotting
d) Phagocytosis and destruction of bacteria
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Correct Answer: d) Phagocytosis and destruction of bacteria
Explanation: Neutrophils are a type of white blood cell that primarily function in phagocytosis, engulfing and destroying bacteria and other small particles. They are an essential part of the innate immune system and act as the first line of defense against infections.