1. Daily News Good Morning 7 th Grade! August 10, 2015 Welcome back! Please grab a do now from your class’ tray by the door. Begin working on it silently. Today we are going to review the scientific method and utilize its steps with a penny experiment! We only have 45 minutes to do all of this! Let’s make every minute count! Scientifically, Ms. McWaters

2. The Scientific Method The method scientists use to solve problems Structured way of experimenting 1.Ask a question 2.Form a hypothesis (prediction) 3.Set up a controlled experiment 4.Record and analyze results 5.Draw a conclusion that agrees with or disagrees with your hypothesis

3. Scientific Method Hypothesis: a prediction intended to explain certain facts or observations. Ex: If a person does not breathe for 10 minutes, then they will die. Or if a paper clip is tossed into the air, then it will come back down. Control Group: The part of your experiment that always remains the same. That way you can always be sure what you are testing is responsible for changes. Ex: type of paper clip used, person tossing the paper clip, person measuring the paper clip going up, etc…

4. Scientific Method Independent Variable (sometimes called manipulated variable)- the variable that is deliberately changed ex: adding weight to the paper clip to see if it changes the speed of falling. Dependent Variable (sometimes called responding variable)- the variable that is observed and that changes in response to the manipulated variable ex: speed of the paper clip falling Conclusion: Whether or not your hypothesis was correct. What you observed about the experiment.

5. Controlled Experiment When you test a hypothesis, you should only change one variable at a time. Variable examples- weight of paper clip, length, & so forth. You only want to change one variable at a time so you can tell which variable is responsible for the observed results.

6. Francesco Redi’s Experiment Francesco Redi Was an Italian physician in 1668. During these times many people believed in spontaneous generation- the idea that life could arise from nonliving matter. For an example maggots showing up on old meat after the meat had been sitting out for days.

7. Francesco Redi’s Experiment He proposed a different hypothesis for the appearance of maggots. Redi had observed the maggots on the meat, just a few days after flies had landed on it. He considered it likely that the flies laid eggs that were too small for the human eye to see. What was his hypothesis?

8. Francesco Redi’s Experiement Based on his hypothesis, Redi made a prediction that keeping flies away from meat would prevent the appearance of maggots. He put meat in two jars. He covered one with gauze. He left the other uncovered. He waited several days. The jar with gauze kept flies from getting in. The jar without gauze allowed flies to get in. What do you think happened?

9. Francesco Redi’s Experiement

10. What was Redi’s Hypothesis? What was the Independent variable? What is the difference that you can see between the two jars at the end of the experiment? What does this say about spontaneous generation?

11. Francesco Redi’s Experiment His hypothesis: Flies produce maggots Controlled Variables: (variables that were the same for both jars at all times)- type of jars, type of meat, location, temperature, time Independent Variable: Gauze covering that keeps flies away Dependent Variable: Whether maggots appear