MCAT Question A Day - 8/15/14 - Answer!
An athlete can engage in blood doping by having blood drawn several weeks before an event, removing the blood cells, and having them reinjected into her body a few days before an athletic activity, Blood doping is most likely an advantage to athletes because:
A. the increased concentration of immune cells in the blood after reinjection can decrease the chances of becoming ill just before the competition.
B. the increased red blood cell count in the blood after reinjection can facilitate greater gas exchange with the tissues.
C. the increased blood volume after reinjection can ensure that the athlete maintains adequate hydration during the event.
D. the decreased red blood cell count of the blood in the weeks before the competition can facilitate training by decreasing the viscosity of the blood.
B is correct. The increased hemoglobin concentration in the blood after reinjection increases the blood's ability to deliver oxygen to the tissues, often a limiting factor in endurance competitions. A is wrong because, while this may happen, it is not the primary benefit of blood doping. B iH a much better answer. C is wrong because, since we are only reinjecting blood cells, we are not increasing the body's hydration status. D is wrong because, while blood is less viscous with fewer red blood cells, we are removing whole blood, not just red blood cells, so we won't be changing the blood's viscosity.
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B is correct. The increased hemoglobin concentration in the blood after reinjection increases the blood's ability to deliver oxygen to the tissues, often a limiting factor in endurance competitions. A is wrong because, while this may happen, it is not the primary benefit of blood doping. B iH a much better answer. C is wrong because, since we are only reinjecting blood cells, we are not increasing the body's hydration status. D is wrong because, while blood is less viscous with fewer red blood cells, we are removing whole blood, not just red blood cells, so we won't be changing the blood's viscosity.
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