Pre-AP Biology Ms. Haut

The Process of Science  The word science is derived from a Latin verb meaning “to know.”  Science is a way of knowing.  Science developed from people’s curiosity about themselves and the world around them.

Hypothesis-Driven Science  As a formal process of inquiry, the scientific method consists of a series of steps.  The key element of the scientific method is hypothesis-driven science.

Scientific Method Observations Question Hypothesis  Prediction Experiment Data Conclusion Retest Communicate Results

Observation You observe something in the material world, using your senses or machines which are basically extensions of those senses. AH—Look at this!

Question You ask a question about what you observe. State the problem or question.

Hypothesis A testable statement about your observation Based on research  You should be able to give reasons for why you chose your hypothesis If/then… statement

Deductive reasoning is used in testing hypotheses –If a hypothesis is supported, and we test it, then we can expect a particular outcome Case study: flashlight failure Figure 1.19

Experiment You figure out a way to test whether the hypothesis is supported.  Control group– nothing changed  Experimental group – one variable changed The outcome must be measurable (quantifiable). Record and analyze data.

Biologists developed a hypothesis regarding mimicry in snakes.  If an animal has certain color patterns, then it will not be preyed upon.  They tested the hypothesis by making artificial snakes and observing how often they were attacked by predators. Figure 1.20

Figure 1.21 This is an example of a controlled experiment.  Such an experiment is designed to compare an experimental group with a control group.  Ideally, a control group and an experimental group differ in only one variable.  Constants: variables that remain the same in all groups

Analyze Results You do the experiment using the method you came up with and record the results. Create data tables, graphs to represent data Perform calculations that will determine what results mean (averages, percentages, totals) Identify possible sources of errors Table 1. Percent of total attacks on different colored artificial snakes.

Draw Conclusions You state whether your hypothesis was supported or not and try to explain your results. Table 1. Percent of total attacks on different colored artificial snakes.

Retest In order to verify the results, experiments must be retested.

Communicate Results Share results with science community

Figure 1.18 ← a tentative answer to some question.

The Culture of Science  Scientists build on what has been learned from earlier research.  They pay close attention to contemporary scientists working on the same problem.  Both cooperation and competition characterize the scientific culture.  Scientists check the conclusions of others by attempting to repeat experiments. Figure 1.22

Evolution Connection: Theories in Science  What is a scientific theory, and how is it different from a hypothesis?  A theory is much broader in scope than a hypothesis.  Theories only become widely accepted in science if they are supported by an accumulation of extensive and varied evidence.