1. What is Biology? Unit 1: Get a Life… Chapter 1: “The Science of Biology”

2. Goals of Science Science—the use of evidence to investigate the natural worldScience—the use of evidence to investigate the natural world Science has 3 goals:Science has 3 goals: –To investigate and understand nature –To explain events in nature –To use those explanations to make useful predictions

3. The Scientific Method ObserveObserve State a Question (Define the Problem)State a Question (Define the Problem) Research (Gather Background Information)Research (Gather Background Information) Form a HypothesisForm a Hypothesis

4. The Scientific Method Experiment (Test the Hypothesis)Experiment (Test the Hypothesis) Record DataRecord Data Analyze DataAnalyze Data Draw a ConclusionDraw a Conclusion

5. Observation The first step in the scientific method is observation.The first step in the scientific method is observation. This involves collecting data using one or more of one’s senses.This involves collecting data using one or more of one’s senses. Data = evidenceData = evidence

6. Inference Once observations have been made, one must make inferences in order to understand the data. Inference = the use of logic to interpret knowledge

7. Hypothesis Hypothesis = an educated guess; a possible explanation for observationsHypothesis = an educated guess; a possible explanation for observations In science, hypotheses are only useful if they can be tested.In science, hypotheses are only useful if they can be tested. Hypotheses may arise from prior knowledge, logical inferences, or imaginative guesses.Hypotheses may arise from prior knowledge, logical inferences, or imaginative guesses.

8. Experiment Experiment = a controlled test of one’s hypothesisExperiment = a controlled test of one’s hypothesis Variable = “to change,” a factor in an experiment that changesVariable = “to change,” a factor in an experiment that changes Control = that to which results can be compared; a constant; a factor that is NOT changed/manipulatedControl = that to which results can be compared; a constant; a factor that is NOT changed/manipulated

9. Variables Two types of variables:Two types of variables: –Independent Variable—a variable that is purposefully changed –Dependent Variable—a variable that is changed BECAUSE of the independent variable

10. Theory Theory = a well-tested explanation that unifies a broad range of observationsTheory = a well-tested explanation that unifies a broad range of observations To become a theory, a hypothesis must:To become a theory, a hypothesis must: –Be tested MANY times –Be VERY well supported

11. Biology “Bio” = life “ology” = study of“Bio” = life “ology” = study of Biology—the scientific study of lifeBiology—the scientific study of life It is the study of living things and the world around them.It is the study of living things and the world around them.

12. Characteristics of Life All living things share several characteristics:All living things share several characteristics: They are made up of units called cellsThey are made up of units called cells They reproduceThey reproduce They are based on a universal genetic code (DNA)They are based on a universal genetic code (DNA)

13. Characteristics of Life They grow and developThey grow and develop They obtain and use materials and energyThey obtain and use materials and energy They respond to their environmentThey respond to their environment

14. Characteristics of Life They maintain a stable internal environment (called homeostasis)They maintain a stable internal environment (called homeostasis) As a group, they change over time (evolve)As a group, they change over time (evolve)