Free GED SCIENCE Exam Braindumps
GED Section 3: Science Questions 71–75 (page: 16)

Scientist Alexander Fleming was looking for a chemical that would be effective in combating bacteria. In order to test various chemicals, he grew cultures of the bacteria, Staphylococcus. One day in 1928, as he was working in his laboratory, Fleming noticed that one of his culture plates had mold growing on it. Many people might have thrown the plate away thinking that it was useless, but Fleming did not. He noticed something--that no bacteria were growing near the mold. He hypothesized that the mold was killing the bacteria. Fleming had just discovered penicillin.
He began working to separate the chemical that killed the bacteria from all the other chemicals in the mold. Unfortunately, he was unable to do so. However, in 1940, two chemists, Ernst Chain and Howard Florey, did manage to separate the chemical penicillin. In 1945, all three men were awarded the Nobel Prize in Medicine.
Based on the information, which statement represents the best conclusion?

If you had a freshwater fish tank in your home, which type of algae would most likely survive in that type of environment?

Each year, approximately 200 million tons of municipal solid waste are generated in the United States. Incineration (burning), recycling, landfills, reduce-reuse, and composting are all possible ways to reduce the amount of waste in this country. When selecting the best approach to this problem, officials must carefully consider the risks and benefits of each method.
Which disposal method will produce the most toxic air pollution?

A newly hatched chicken will peck at any spots on the ground that are a color different from the ground. This behavior is instinctive and only about 15 percent of the pecks lead to food. However, with time, the chick's accuracy in using pecks to pick up food improves.
To what can we attribute this more accurate feeding behavior?

A major volcanic eruption put large amounts of dust into the upper atmosphere. For three years following the eruption, Earth's weather was cooler than normal. Which of the following is NOT a testable hypothesis regarding the relationship between the eruption and the weather?