Scientific Method, Macromolecules, & Water EOC Review

Megan is talking with her brother about a scientific theory that she is studying. “I don’t believe what the scientists say, because that’s just a theory,” her brother says. “If those scientists were certain, then it would be a law, not just a theory.”

Which statement explains their misunderstanding?

• Her brother has a misconception that theories become laws and is confusing the scientific use of theory with the everyday use.

• Her brother is confusing the meanings of scientific law and scientific theory.

• Her brother has a misconception about the types of questions that science can answer and which are addressed by other ways of knowing.

• Her brother is confusing the meanings of the terms theory and hypothesis.

Valerie designed and conducted an experiment on pothos plants, which are common houseplants. Her hypothesis is that the direction of light will affect the growth pattern of a pothos plant. To test the hypothesis, she sets up two test groups of pothos plants and observes them three weeks later. The table summarizes the test groups and observations.

What are the roles of the two test groups in this investigation?

• Both are experimental groups, and each individually shows the effect of the direction of light.

• One is the experimental group and one is the control group, and together they show the effect of the direction of light.

• One is the experimental group and one is the control group, and together they show the effect of the direction of light.

• Both are experimental groups, but only Test Group 1 shows the effect of the direction of light.

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Evolutionary theory has become the central organizing principle of biological science. Could this scientific theory ever become a scientific law?

• Yes, if scientists decide that enough evidence supports the theory.

• Yes, if the theory is shown to predict future events.

• No, because a theory is a complex explanation that does not become a law.

• No, because a theory can be proven correct while a law cannot be proven.

After a team of scientists completes an investigation, they submit an article about the investigation to a scientific journal. Before the journal publishes the article, they send it to other scientists for an anonymous, independent review. What is the purpose of this review?

• to evaluate the methods and test the results of the investigation

• to guarantee that the conclusions of the investigation are correct

• to make sure the investigation has practical, economic benefits

• to improve the appeal of the article to the general public

When news of a scientific discovery is reported, readers must assess the credibility of the claim. For scientific discoveries in general, which statement indicates a valid and credible claim?

• The scientist aimed for precision and accuracy by using a small sample size.

• The scientist followed strict standards of investigation and scientific methodology throughout the research.

• The scientist assured that the experiment was broad in scope by testing many variables in each trial.

• No other scientists replicated the experiment to avoid the legal issues of patent infringement.

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A group of students conducted a science fair experiment to find out how the amount of fertilizer used will affect the growth of radish plants. The experiment was done using amounts of fertilizer that were less than and greater than the manufacturer’s recommendation. The table shows the average plant height in each test group after 10 days.

Which inference is supported by the data?

• Giving radish plants too little or too much fertilizer will not affect plant growth.

• Giving radish plants too little or too much fertilizer will slow down plant growth.

• Giving radish plants more fertilizer will increase plant growth.

• Giving radish plants less fertilizer will increase plant growth.

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How is the word theory used in science?

• Scientists use the word theory when they mean that they have a hunch or a guess.

• Scientists use the word theory when a single hypothesis is well supported by a wide body of evidence.

• Scientists use the word theory when it applies to a tested, highly reliable scientific explanation of events in the natural world.

• Scientists use the word theory when they are not certain about an idea.

The disease polio once sickened thousands of children every year. The graph depicts the number of polio cases that occurred between 1952 and 1973, based on information from the U.S. Department of Health, Education, and Welfare and the Centers for Disease Control. The data best support which of these statements?

• Introducing a vaccine for polio had no effect on the number of cases of polio diagnosed each year.

• The polio vaccine was effective in protecting thousands of people from this disease.

• The vaccine proved ineffective because cases of polio rose between 1957 and 1959.

• The sources of the data are not reliable and, therefore, the data should be ignored.

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The diagram shows the structure of glucose, a molecule that organisms make and use.

Glucose and similar molecules can be joined together to form polymers called polysaccharides. There are several types of polysaccharides, and each performs different functions in living organisms. Which of the following is not a type and function of polysaccharides?

• wax, for structure

• cellulose, for structure

• glycogen, to store sugar for energy

• starch, to store sugar for energy

What function in living things do glucose and similar molecules fulfill?

• They regulate cell processes.

• They form waterproof coverings.

• They transmit genetic information.

• They store and release energy.

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