Chapter 1: The Science of Biology Marcellin Biology

What is SCIENCE? The goal of science is The goal of science is 1. Investigate and understand the natural world 2. Explain events in the natural world 3. Use explanations to make useful predictions

What is SCIENCE? Science is different because Science is different because 1. Deals only with the natural world 2. Scientists collect and organize information in a careful, orderly way. They look for patterns and connections among events. 3.Scientists propose explanations that can be tested by looking at evidence.

What is SCIENCE? An organized way of using evidence to learn about the natural world. An organized way of using evidence to learn about the natural world.

What is SCIENCE? This “organized way” is also called … This “organized way” is also called … THE SCIENTIFIC METHOD! THE SCIENTIFIC METHOD!

What is SCIENCE? Science is an ongoing process. Science is an ongoing process. Good scientists must be skeptical. They must constantly question existing ideas and new hypotheses. Good scientists must be skeptical. They must constantly question existing ideas and new hypotheses.

The Scientific Method 1. Problem 1. Problem 2. Hypothesis 2. Hypothesis 3. Procedure 3. Procedure Controlled Experiment a. Manipulated (Independent) Variable This is deliberately changed. (ex. temperature, amount of light) THERE IS ONLY 1 MANIPULATED VARIABLE IN AN EXPERIMENT!!!!

The Scientific Method 3. Procedure (continued) 3. Procedure (continued) b. Responding (Dependent) Variable This changes in response to the manipulated variable. (ex. The height of a plant) c. Control Group Does not receive a variable Used for comparison

The Scientific Method 4. Data 4. Data 5. Conclusion 5. Conclusion 6. Publish results 6. Publish results

What happens if a hypothesis is well- supported? It becomes a THEORY. It becomes a THEORY. Theory- Well tested explanation that unifies a broad range of observations. Theory- Well tested explanation that unifies a broad range of observations.

A Controlled Experiment Hypothesis: What is the effect of environment on a rabbit’s fur color? Hypothesis: What is the effect of environment on a rabbit’s fur color? We already know: We already know: The rabbit normally has a white coat, except for its nose, feet, tail, and ears which are black. The rabbit normally has a white coat, except for its nose, feet, tail, and ears which are black.

A Controlled Experiment Procedure: Procedure: 1. Shave an area of hair on 2 rabbits. 1. Shave an area of hair on 2 rabbits. 2. Place an ice pack over the shaved area on one rabbit (A). 2. Place an ice pack over the shaved area on one rabbit (A). Results: Results: Rabbit A developed a black patch of fur where the ice pack was. Rabbit A developed a black patch of fur where the ice pack was. Rabbit B stayed the same. Rabbit B stayed the same.

A Controlled Experiment What can we conclude? What can we conclude? Cold temperatures changes the rabbit’s fur color to black. Cold temperatures changes the rabbit’s fur color to black. Which rabbit is the control group? Which rabbit is the control group? What is the manipulated variable? Responding? What is the manipulated variable? Responding? Why do we need Rabbit B? Why do we need Rabbit B?