Scientific Method 1

Which statement best describes a scientific theory?

• A - It is a collection of data designed to provide support for a prediction
• B - It is an educated guess that can be tested by experimentation
• C - It is a scientific fact that no longer requires any evidence to support it
• D - It is a general statement that is supported by many scientific observations.

Researchers performing a well-designed experiment should base their conclusions on

• A - the hypothesis of the experiment
• B - data from repeated trials of the experiment
• C - a small sample size to insure a reliable outcome of the experiment
• D - results predicted before performing the experiment

The analysis of data gathered during a particular experiment is necessary in order to

• A - formulate a hypothesis for that experiment
• B - develop a research plan for that experiment
• C - design a control for that experiment
• D - draw a valid conclusion for that experiment

A scientist is planning to carry out an experiment on the effect of heat on the function of a certain enzyme. Which would not be an appropriate first step?

• A - doing research in a library
• B - having discussions with other scientists
• C - completing a data table of expected results
• D - using what is already known about the enzyme

Why do scientists consider any hypothesis valuable?

• A - A hypothesis requires no further investigation.
• B - A hypothesis may lead to further investigation even if it is disproved by the experiment
• C - A hypothesis requires no further investigation if it is proved by the experiment.
• D - A hypothesis can be used to explain a conclusion even if it is disproved by the experiment.

In Texas, researchers gave a cholesterol-reducing drug to 2,335 people and an inactive substitute (placebo) to 2,081. Most of the volunteers were men who had normal cholesterol levels and no history of heart disease. After 5 years, 97 people getting the placebo had suffered heart attacks compared to only 57 people who had received the actual drug. The researchers are recommending that to help prevent heart attacks, all people (even those without high cholesterol) takes these cholesterol-reducing drugs. In addition to the information above, what is another piece of information that the researchers must have before support for the recommendation can be justified?

• A - Were eating habits of the two groups similar?
• B - How does a heart attack affect cholesterol levels?
• C - Did the heart attacks result in deaths?
• D - What chemical is in the placebo?

"Garlic grows better as the salt concentration of the solution in which it is grown increases."        Describe the control to be used in the experiment.

• Garlic bulb in pure water
• Garlic bulb in a solution with high a salt concentration
• Garlic bulb in a solution with a low salt concentration
• Garlic bulb in a solution with a high glucose concentration

A biologist reported success in breeding a tiger with a lion, producing healthy offspring. Other biologists will accept this report as fact only if

• A - research shows that other animals can be crossbred
• B - the offspring are given a scientific name
• C - the biologist included a control in the experiment
• D - other researchers can replicate the experiment

Though scientists study the world from differing perspectives, what must all scientists take into account?

• A - universal laws
• B - animal behavior
• C - temperature differences
• D - the importance of biology

A student hypothesized that lettuce seeds would not sprout (germinate) unless they were exposed to darkness. The student planted 10 lettuce seeds under a layer of soil and scattered 10 lettuce seeds on top of the soil. The data collected are shown in the Data Table #9 above.One way to improve the validity of these results would be to

• A - conclude that darkness is necessary for lettuce seed germination
• A - conclude that darkness is necessary for lettuce seed germination
• C - revise the hypothesis
• D - repeat the experiment