Problem: Tim and Dan both studied reproduction in college. Dan studied plant reproduction while Tim studied fish reproduction. Which person studied less about the way fish reproduce? Hint: Fish reproduce sexually. They lay eggs that can be fertilized either inside or outside of the body. In most fish, the eggs develop outside of the mother's body. In the majority of these species, fertilization also takes place outside the mother's body. The male and female fish release their gametes into the surrounding water, where fertilization occurs. Female fish release very high numbers of eggs to increase the chances of fertilization.

A: Dan

Problem: The biologists found out that the Indian Ocean had a lower water pH than it did a decade ago, and it became acidic. The water in the Arctic ocean still had a neutral to basic pH. Which ocean has a lower content of carbon dioxide in its waters? Hint: Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic. Burning fossil fuels has led to an increase in carbon dioxide in the atmosphere. This carbon dioxide is then absorbed by the oceans, which lowers the pH of the water. Ocean acidification can kill corals and shellfish. It may also cause marine organisms to reproduce less, which could harm other organisms in the food chain. As a result, there also may be fewer marine organisms for humans to consume.

A: Arctic

Problem: In the town of Hawkings they get all of their power from a Nuclear power plant. Across the country another town called Gideon relies solely on the burning of fossil fuels. Gideon intents to switch to nuclear power soon. Which town produces more air pollution, Gideon or Hawkings? Hint: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy.

A: Gideon

Problem: Mike and John are brothers. Their dad sent them to the doctor's office to get tested for hepatitis because Mike was feeling sick all the time. It turned out Mike has hepatitis B, while John doesn't. Which brother had a disease of the liver? Hint: Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B.

A:
Mike