[Q]: Joe studied the lives of humans. He studied 2 groups of people. Group G had people over 65 in it, and group Y had people under 65 years old in it. Which group had more people that were retired from work? Hint: Old age begins in the mid-60s and lasts until the end of life. Most people over 65 have retired from work, freeing up their time for hobbies, grandchildren, and other interests. Stamina, strength, reflex time, and the senses all decline during old age, and the number of brain cells decreases as well. The immune system becomes less efficient, increasing the risk of serious illnesses such as cancer and pneumonia. Diseases such as Alzheimer's disease that cause loss of mental function also become more common.
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[A]: Group G

[Q]: Two brothers went on vacation. Tom partied heavily, and found out that he was infected with the HIV virus. Tim was more moderate, he went to the beach to get a sun tan, but he got an infection as well. Tim found out he got a bacterial infection and had to take antibiotics. Which brother had a greater chance of developing AIDS? 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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[A]: Tom

[Q]: Two groups of students learned about protozoa for a school project. Group P studied more about predatory protozoa, while group G studied about grazing and parasitic protozoa, plus portozoa as food sources. Which group learned less about protozoa keeping bacterial populations in check? Hint: Protozoa generally feed by engulfing and digesting other organisms. As consumers, they have various roles in food chains and webs. Some are predators. They prey upon other single-celled organisms, such as bacteria. In fact, protozoa predators keep many bacterial populations in check. Other protozoa are herbivores. They graze on algae. Still others are decomposers. They consume dead organic matter. There are also parasitic protozoa that live in or on living hosts. For example, the protozoan that causes malaria lives inside a human host. For their part, protozoa are important food sources for many larger organisms, including insects and worms.
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[A]: group G

[Q]: Patty was a runner and liked hiking so she spent a lot of time outdoors. Her friend Fay sealed up her home and spent most of her time indoors. Both friends lived in an area with moderate to high levels of air pollution and attended a seminar where they learned more about the impact of air pollution on human health. Which friend was exposed to more indoor pollution? Hint: Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesn't get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk.
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[A]:
Fay