Theories, Hypotheses, and Laws

What is the best definition of the term "theory," as it is used in science?

• a.A theory is a guess or hunch about something that has occurred in nature.
• b.A theory is a comprehensive set of ideas explaining a phenomenon in nature.
• c.A theory is based on verifiable laws and can be proven true.
• d.A theory is a hypothesis that uses laws and observation to make an assumption.

While speaking to a colleague, a scientist makes the following statement: "I propose that Bald Eagle eggs in northern Maine will have thinner shells than those from birds in southern Alaska due to increased levels of pesticides in the water." This statement is a

• a.theory
• b.law
• c.conclusion
• d.hypothesis

Scientific theories can be tested.

• a.true
• b.false

Complete the following sentence so that it is correct: Scientific theories are based on

• a.general assumptions of how systems work.
• b.mathematical principles that can be proven true.
• c.large amounts of data collected over time.
• d.observations from within only one scientific discipline.

Why are scientific theories an important part of research and understanding?

• a.Scientific theories allow scientists to make predictions.
• b.Scientific theories allow scientists to make assumptions.
• c.Scientific theories determine the work that future scientists can do.
• d.Scientific theories determine the subjects that scientists research.

Scientific theories do not change once they have been written down.

• a.true
• b.false

Which statement below correctly identifies the difference between laws and theories?

• a.Laws describe phenomena, while theories explain why phenomena exist.
• b.Laws are a statement of fact, while theories are a statement of opinion.
• c.Laws explain why phenomena exist, while theories explain how.
• d.Laws are a prediction of phenomena, while theories are an explanation.

Why do scientists develop a hypothesis before conducting research?

• a.It gives them direction on how to interpret the results of their research.
• b.It helps to predict outcomes and define the parameters of the research.
• c.Hypotheses give the researcher an outcome to shape their work around.
• d.Hypotheses help a researcher decide which observations to record and which to ignore.

Scientific theories are always broad and cover many concepts.

• a.true
• b.false

Choose the sentence below that is a correct description of scientific theory.

• a.Scientific theories in one discipline can influence theories in other disciplines.
• b.Theories in one scientific discipline do not affect theories in other disciplines.
• c.New scientific theories are always original and do not connect to those that came before.
• d.Creativity and insight are not important parts of developing new scientific theories.