Nature of Science EOC Review

For her science fair project, Samantha would like to see how different substances affect bone mass. She collects several chicken leg bones from the grocery store, records each bone’s mass, and soaks them in different liquids for 48 hours. After 48 hours Samantha measures the mass of each bone again. Below is a data chart of Samantha’s experiment. Based on the data chart, which liquid caused the most bone loss?

• coffee

• diet soda

• lemon juice

• milk

Paul is writing a research paper for his Anatomy and Physiology course on increased risk factors of high blood pressure. The research states that smoking cigarettes increases the chances of hypertension. Paul decides to collect blood pressure data on people who state they smoke at least 10 cigarettes in a day and on those who do not smoke.

What is the independent (test) variable in Paul’s experiment?

• smoking cigarettes

• age range of participants

• the measure of blood pressure

• the number of cigarettes smoked in a day

Why is a hypothesis important to a scientific investigation?

• Without a hypothesis, there is no way to tell if you did an experiment correctly.

• Without a hypothesis, you have no statement to tell you if your results are correct.

• Without a hypothesis, there is no way to tell if you have done enough research about the problem.

• Without a hypothesis, you have no statement to which you can compare your results to in order for you to determine what those results mean.

Scientists are performing an investigation to determine how a food source affects muscle development. The scientists raise frogs from tadpoles and then separate the frogs into different groups. Each group receives a different type of food. Which set of data would provide the best evidence that a certain food source is better for muscular development of frogs?

• the color of the skin once the frog reaches adult size

• the volume of the croak once the frog reaches adult size

• the distance the frog can jump once the frog reaches adult size

• the number of offspring produced once the frog reaches adult size

Which statement best describes a scientific theory?

• It is a scientific fact that no longer requires any evidence to support it.

• It is a collection of data designed to provide support for a prediction.

• It is an educated guess that can be tested by scientific experimentation.

• It is a general statement that is supported by many scientific observations.

For many years, many people associated stomach ulcers with eating spicy foods. Later research showed that a particular bacterium living inside the highly acidic environment of the stomach produced a coating that attacked the stomach lining. This process led to the formation of stomach ulcers. These findings sent researchers looking for an antibiotic that could treat the problem bacteria. Subsequent studies found a host of antibiotics that effectively treat the bacteria and lead to the healing of the ulcers. Which of the following does the history of ulcers and their treatment best illustrate?

• Scientific knowledge is not open to change once explanations of phenomena have been established.

• Scientists base their knowledge on opinions about explanations of phenomena in nature.

• Scientists in the same research group tend to view data in the same way.

• Unexpected findings can cause scientists to rethink earlier hypotheses.

A mineral supplement designed to prevent the flu was given to two groups of people during a scientific study. Dosages of the supplement were measured in milligrams per day, as shown in the table below.

SUPPLEMENT DOSAGES

Group Dosages (mg/day)

A 100

B 200

After 10 weeks, neither group reported a case of the flu. Which of the following would constitute a control in the experiment?

• If the test included only the group given 200 mg of the supplement.

• If the test included a third group that received 150 mg of the supplement.

• If the test included a third group that received 0 mg of the supplement.

• If the test included only the group given 100 mg of the supplement.

A student learned that human teeth consist mainly of a compound called hydroxyapatite. The student designed an experiment to test how teeth respond to different pH levels. The student tested a sample of solid hydroxyapatite and found that it was insoluble in water. The hydroxyapatite dissolved upon addition to an acidic solution. Which of the following reasons best explains why the student tested the acidic solution on a sample rather than on a living tooth?

• to determine whether a living person would experience discomfort if tested

• to determine whether hydroxyapatite reacts just as a living tooth would

• to protect the integrity of the sample

• to avoid possibly harming a person

Leonardo da Vinci’s drawing of the Vitruvian Man is an illustration of the Virtruvian theory. Marcus Virtruvian was a Roman engineer and architect who theorized human body parts fit proportionately inside a circle. According to the theory, the distance from fingertip to fingertip is the same distance as the height. Which of the following most likely helped people to accept the Virtruvian theory?

• Ancient drawings were found that supported the Virtruvian theory.

• The Virtruvian theory won’t become accepted until it becomes a law.

• A lot of scientific evidence was gathered that supported the Virtruvian theory.

• Another scientist wrote an article supporting the Virtruvian theory at the same time.

William Harvey studied the human circulatory system during the mid-1600s. He suspected that tiny vessels must bring blood from the arteries to individual cells. However, because of the limitations of technology available at that time, Harvey was unable to view the small vessels. In 1661, Malpighi used the newly invented microscope to actually view these small vessels, which he called capillaries. His work confirmed Harvey's hypothesis concerning the movement of blood in the body. Which of the following best describes what this story illustrates?

• Scientists have a responsibility to share their findings with each other.

• Lack of technology never hinders the search for natural phenomena.

• New findings in science often come from a number of contributors.

• Many discoveries in science result from accidental discoveries.