Ap biology 2017-2018

1. Ap biology2017-2018 Notes/Homework Section 1.3 Campbell Biology in Focus

2. Biological inquiry entails forming and testing hypotheses based on observations of nature • The word science is derives from a Latin verb meaning ‘to know.’ • Inquiry is the search for information and explanation. • The scientific process includes making observations, forming logical hypotheses, and testing them. • Recorded observations are called data. Observations can occur before or after a hypothesis is made and tested. • There are two categories of data: • Qualitative data – descriptions rather than measurements • Quantitative data – recorded measurements

3. Types of reasoning • Inductive reasoning – from the specific to the general • Example: all organisms examined are made of cells – therefore, all organisms are made of cells • Deductive reasoning – from the general to the specific • Example: all organisms are made of cells – therefore, this organism is made of cells • Deductive reasoning only works if the premise (hypothesis) is correct – scientists use the hypothesis to make a prediction and then test that prediction using an experiment. • A hypothesis can never be conclusively proven to be true because we can never test all the alternatives. • Hypotheses gain credibility by surviving multiple attempts to falsify them. A hypothesis must be testable and falsifiable.

4. Experiments • A controlled experiment is used to test a hypothesis. It is ‘controlled’ because an attempt is made to test only one variable at a time. • Additionally, it is considered a ‘controlled’ experiment because the results of the experimental group are compared to a control group, which does not receive the variable that is being tested. The control group is treated exactly the same as the experimental group except for the variable being tested. • The variable being tested is the independent variable. It is what the scientist changes between the control and the experimental groups. • The result of this change is the dependent variable – so named because it should change due to the effect of the independent variable.

5. Theory • In science it doesn’t make any sense to say something is unlikely to be true because it is ‘just a theory.’ • In science, a theory is: • Used to explain a wide range of observations • Broader in scope than a hypothesis • General enough to lead to new hypotheses • Supported by a large body of evidence

6. Homework Questions 1-3(Note: You may also need to reference your textbook, pages 11-16) • Define data. Distinguish between qualitative and quantitative data. • What is inductive reasoning? How is this different from deductive reasoning? • What does it mean to say that a scientific hypothesis must be falsifiable? • What is a controlled experiment? • What is a scientific theory and how is it different from a hypothesis?

7. Scientific Skills Exercise • Read Interpreting a Pair of Bar Graphs, page 15 • Answer questions 1-7

8. Chapter Review • Answer multiple choice questions #1-6 , page 17 • Answer the short-answer question #10, page 17