1. Chapter 1 The Science of Biology The Scientific Method

2. What is Science?  Science– Latin for ‘to know’  Science is an organized way of using evidence (observations and data collection) to learn about the natural world

3. Scientific Method  An organized way of solving problems –1.Observations –2. Problem statement –3.Hypothesis –4.Experimental design –5.Record results –6.Draw conclusions

4. Scientific Method Observations and Questions  1.Observations –What you see/provide raw data –Inferences are your logical interpretations of what you see.  2. Problem Statement: –The question –The reason behind the experiment

5. Scientific Method  An organized way of solving problems –1.Observations –2. Problem statement –3.Hypothesis –4.Experimental design –5.Record results –6.Draw conclusions

6. Scientific Method Hypothesis  2.Hypothesis-a suggested explanation/answer to a question  Must be testable!  Prediction of the hypothesis in form of –“If……then……” –If I put fertilizer on my plants, then they will grow bigger

7. Scientific Method  An organized way of solving problems 1.Observations 2. Problem statement 3.Hypothesis 4.Experimental design 5.Record results 6.Draw conclusions

8. Scientific Method Experimental Design  3.Experimental design- designed to test hypothesis  Split subjects you are testing into groups: #1 Experimental Group-given the experimental factor or changed in some way #2 Control Group:-NOT changed Experimental Group Fertilizer Control Group No Fertilizer

9. Scientific Method Experimental design  Variable-factor in experiment that is subject to change. –Manipulated variable (Independent Variable)- factor in experiment that’s purposely manipulated (changed)— fertilizer –Responding variable (dependent variable)—factor that a scientist observes for responses in—plant height and ?  Only test ONE manipulated variable while keeping others the same

10. Francesco Redi’s Experiment Attempting to disprove Spontaneous Generation  Common Beliefs of the Time  Frogs and Turtles come from mud and rotting wood.  Mice come from straw.  Flies come from rotting meat.  Most of these ideas remained from the time of Aristotle. Why would people believe this?

11. Redi’s Experiment: Step 1  Redi knew that flies often appeared on and around rotting meat. So, he placed rotting meat in three jars.

12. Redi’s Experiment: Step 2  In the first jar, Redi left the jar open to the air.

13. Redi’s Experiment: Step 3  On the 2nd jar, Redi placed a cover on the jar. The flies could not smell the meat, nor could they land in the meat.

14. Redi’s Experiment: Step 4  On the 3rd jar, Redi placed a gauze or netting over the jar. The flies could smell the meat, but could not land on the meat.

15. Results?  What would you expect the results of this experiment to be?

16. Results  In the first jar, the flies could lay their eggs on the rotting meat, maggots would appear and later grow into flies.  In the second jar, the flies could not smell the meat, or land on it, so they would lay their eggs somewhere else.  In the third jar, the flies could smell the meat, so they would lay their eggs on the netting thinking there was a food source for the maggots.

17. Scientific Method Experimental Design  Must be a controlled, reproducible procedure Testing effects of only ONE manipulated variable Other scientists need to be able to reproduce it and prove your results valid.

18. Experimental Set Up EXPERIMENT EXPERIMENTAL GROUP Check the results in time CONTROL GROUP Difference is the manipulated variable Compare the responding variable Check the results in time

19. Scientific Method  An organized way of solving problems 1.Observations 2. Problem statement 3.Hypothesis 4.Experimental design 5.Record results 6.Draw conclusions

20. Scientific Method Results  4. Results –Record data –Qualitative data -physical traits (qualities) that can be described –Quantitative data -measurements (quantities) that can be taken –Pictures, tables, graphs –Trends noticed

21. Scientific Method Results Qualitative? Quantitative? Qualitative? Quantitative? Experimental Group Control Group fertilizer no fertilizer fertilizer no fertilizer

22. Scientific Method  An organized way of solving problems 1.Observations 2. Problem statement 3.Hypothesis 4.Experimental design 5.Record results 6.Draw conclusions

23. Scientific Method Drawing Conclusions  5.Conclusions –Uses evidence to accept or reject the hypothesis –Hypothesis is NEVER “PROVEN!”  If supported  further testing  If rejected  hypothesis changed and tested again  Can be partly true  Findings always useful!!!

24. Scientific Methods What a Theory Is/Is Not  Theory-a well-supported explanation of some aspect of the natural world –***It’s the closest you can get to scientific fact –It’s a hypothesis than has been tested and supported many times –Used to make future predictions –Not “a hunch” like it means in everyday language –If contradictory evidence found, theory revised or replaced –There is no evidence against them  A hypothesis is a POSSIBLE explanation, whereas a theory IS an explanation

25. Scientific Method Models  Science’s way of strutting it’s stuff!  Representations of how we believe processes or ideas work  Used to predict  In forms of computer programs, graphs, images, objects, equations  Not exact replicas

26. Scientific Method Overview Section 1-2 State the Question or Problem Form a Hypothesis Set Up a Controlled Experiment Record Results Draw a Conclusion Publish Results

27. Science in Context  What scientific attitudes help generate new ideas?  Why is peer review important?  What is a scientific theory?  What is the relationship between science and society?