Blood doping (using injected substances to artificially enhance performance) is illegal in many sports. two substances used are erythropoietin and hypoxia-inducible factors (hif). one of the actions of hif is to increase formation of new blood vessels (angiogenesis). explain how administering erythropoietin can increase performance and how hif can increase performance through angiogenesis.

Hiv is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. what are the practical consequences of these findings? a) hiv can be transmitted more easily from person to person than the flu virusb) the flu virus can be transmitted more easily from person to person than hivc) this property of hiv makes it more likely to be a pandemic than the flu virusd) disinfecting surfaces is more important to reduce the spread of hiv than the flu