Two friends had different diseases. Nigel was more prone to viral infections, so one day he got infected with the HIV virus. Manny had contracted some sort of bacterial infection. Which friend received fewer vaccinations? Hint: While people have been able to prevent certain viral diseases by vaccinations for many hundreds of years, the development of antiviral drugs to treat viral diseases is a relatively recent development. Antiviral drugs are medications used specifically for treating the symptoms of viral infections. The first antiviral drug was interferon , a substance that is naturally produced by certain immune cells when an infection is detected. Over the past twenty years the development of antiretroviral drugs (also known as antiretroviral therapy, or ART) has increased rapidly. This has been driven by the AIDS epidemic.
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Answer: Manny

Dan and Joe studied animals for biology class. Joe had to study predator animals, while Dan studied herbivores and grazers. Which student learned more about the balance of organisms in an ecosystem? Hint: Predators play an important role in an ecosystem. For example, if they did not exist, then a single species could become dominant over others. Grazers on a grassland keep grass from growing out of control. Predators can be keystone species . These are species that can have a large effect on the balance of organisms in an ecosystem. For example, if all of the wolves are removed from a population, then the population of deer or rabbits may increase. If there are too many deer, then they may decrease the amount of plants or grasses in the ecosystem. Decreased levels of producers may then have a detrimental effect on the whole ecosystem. In this example, the wolves would be a keystone species.
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Answer: Dan

Phillip just came home to his apartment after taking a long, vigorous bike ride. He enters the front door to find his roommate, Brandon, sitting on the couch playing videogames and eating potato chips. Phillip tells Brandon that if he keeps being so lazy and snacking so much he's going to start looking chubby. Brandon just waves Phillip off and goes back to his game. Whose heart is pumping less blood? Hint: In exercises such as weight lifting, skeletal muscle contracts against a resisting force (see Figure below ). Using skeletal muscle in this way increases its size and strength. In exercises such as running, the cardiac muscle contracts faster and the heart pumps more blood. Using cardiac muscle in this way increases its strength and efficiency. Continued exercise is necessary to maintain bigger, stronger muscles. If you don't use a muscle, it will get smaller and weakerso use it or lose it.
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Answer:
Brandon