1. What is Science? Section 1.1

2. What Science Is and Is Not ► Science ► Organized way of using evidence to learn about the natural world

3. What Science Is and Is Not Cont’d ► Goal of Science: ► Investigate and understand the natural world ► Explain events ► Use explanations to make predictions that could be beneficial

4. Thinking Like A Scientist ► Step 1 ► Observation: ► Process of gathering info. about events or processes in a careful, orderly way

5. Thinking Like A Scientist Cont’d ► Step 2 ► Gathering info. from observations (data) ► 2 Types of Data ► 1. Quantitative: expressed as numbers ► 2. Qualitative: descriptive and involve characteristics that can’t easily be measured

6. Thinking Like A Scientist Cont’d ► Step 3 ► Make inferences based on data ► Inference ► Logical interpretation based on prior knowledge or experience

7. Thinking Like A Scientist Cont’d ► Step 4 ► Explain and interpret your evidence which leads to a… ► Hypothesis ► Proposed scientific explanation for a set of observations that can be tested

8. Hypothesis ► Must be proposed in a way that can be tested ► Tested by performing controlled experiments or by gathering new data

9. Explaining and Interpreting Evidence ► Do not copy ► Researchers often work in teams to analyze, review, and critique each other’s data and hypotheses. ► A review process helps ensure conclusions are valid. ► To be valid, a conclusion must be based on logical interpretation of reliable data.

10. What does science involve? 1. Asking questions 2. Observing 3. Making inferences 4. Testing hypotheses

11. Science as a Way of Knowing ► Scientific knowledge is always changing ► Good scientists are skeptics

12. Science and Human Values ► Decisions in science depend on: ► Society ► Economy ► Laws ► Moral principles ► We decide what and how things get done when we vote

13. Section 1-2

14. The Scientific Method Section 1-2 ► How do scientists test hypotheses? ► Controlled Experiments ► Must change only 1 variable at a time ► Why??????????

15. Designing an Experiment ► Steps: 1. Ask a question 2. Form a hypothesis 3. Set up a controlled experiment 4. Record/Analyze results 5. Draw conclusion

16. Designing an Experiment Cont’d ► Step 1: Asking a question ► Ex.) ► How do organisms come into being?

17. Designing an Experiment Cont’d ► Step 2: Forming a hypothesis ► Ex.) Spontaneous Generation ► Life could come from nonliving matter ► People thought maggots came from meat ► 1668, Redi proposed a different hypothesis ► Maggots came from eggs that flies laid on meat

18. Designing an Experiment Cont’d ► Step 3: Setting up a controlled experiment ► Manipulated Variable ► Deliberately changed ► Responding Variable ► Variable that is observed and that changes in response to the manipulation

19. Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Controlled Variables: jars, type of meat, location, temperature, time Covered jars Uncovered jars

20. Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Manipulated Variable: Gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear. Several days pass. No maggots appear.

21. Designing an Experiment Cont’d ► Step 4: Recording and analyze results ► Use written records of observations/data ► Use drawings when needed ► Use computers to analyze data ► Store data online for others to view

22. Designing an Experiment Cont’d ► Step 5: Draw a conclusion ► Use data to evaluate hypothesis and draw a conclusion ► Ex.) Redi’s results supported his hypothesis

23. Designing an Experiment Cont’d ► Finally Step 6: ► Investigations must be repeated ► Why???? ► To make sure results are correct

24. Repeating Investigations ► Needham ► Challenged Redi’s results ► Said that spontaneous generation could occur when conditions were right

25. Copyright Pearson Prentice Hall Repeating Investigations  Spallanzani's Test of Redi's Findings  Spallanzani's Test of Redi's Findings Gravy is boiled.

26. Copyright Pearson Prentice Hall Repeating Investigations  Spallanzani's Test of Redi's Findings  Spallanzani's Test of Redi's Findings Flask is open. Flask is sealed.

27. Copyright Pearson Prentice Hall Repeating Investigations  Spallanzani's Test of Redi's Findings  Spallanzani's Test of Redi's Findings  This backed up Redi’s findings Gravy is teeming with microorganisms. Gravy is free of microorganisms.

28. Repeating Investigations ► Louis Pasteur ► Disproved the hypothesis of spontaneous generation for sure ► Showed all living things come from other living things

29. Copyright Pearson Prentice Hall Repeating Investigations Pasteur’s Experiment Broth is boiled Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms.

30. Impact of Pasteur’s Work ► Saved the French wine industry b/c it gave them a way to preserve wine to keep it from souring ► Saved silk industry b/c it was becoming endangered by a silkworm disease ► Began to uncover the nature of infectious diseases, showing they came from organisms

31. Question ???? ► How does a scientific theory develop?

32. How A Theory Develops ► Evidence builds over time ► Hypothesis that is supported by it becomes so well supported ► It must then be considered a theory ► Theory ► Well-tested explanation that unifies a broad range of observations ► These can be changed; they are not concrete

33. What is Biology ► Bio/logy- ► Science that employs the scientific method to study living things

34. Characteristics of Life Fig. 1-15 p.16-17 ► Made of cells ► Reproduce ► Based on a universal genetic code ► Grow and develop ► Obtain and use materials and energy ► Respond to environment ► Maintain a stable enviro. ► Change over time as a group

35. Big Ideas ► What do you think this means? ► All biological sciences are tied together they overlap each other p.18-19 ► Go over pg. 18-20 with class

36. Branches of Biology ► Zoology ► Botany ► Paleontology

37. Levels of Organization ► Biosphere ► Ecosystem ► Community ► Population ► Organism ► Groups of cells ► Cells ► Molecules

38. Tools and Procedures ► What units are used to measure things? ► Metric System ► How do scientists analyze data? ► Use graphs

39. Tools and Procedures Cont’d ► Lab Techniques ► Cell Cultures- ► Group of cells grown in a nutrient solution from a single original cell ► Cell Fractionation- ► Solution is put into a centrifuge and spun to separate materials out by densities

40. Microscopes ► 2 Types ► 1. Light- produce images by focusing light rays ► 2. Electron- produce images by focusing beams of electrons

41. History of Microscope ► Use notes from West Greene here