1. Biological Experiments Learning Goals 1, 3-4

2. Lab Equipment • Microscopes: • Light Microscope 40x – 1,000x magnification • Electron microscope 1000x – 100,000x • Models improve understanding • Classroom models • Computer models

3. Experiments • Must test only 1 variable (manipulated) • Experimental (Variable) Group • 1 Manipulated (Independent) Variable • Changed by the scientist on purpose • Difference at the beginning of an experiment • 1 Responding (dependent) Variable • Observed change during the experiment • Data recorded at the end of an experiment • Control Group • Identical to the Experimental Group except for the manipulated variable

4. Redi’s Experiment • Q/P: Can life come from non-life? • Hypothesis: (put your hypothesis here)

5. Redi’s Experiment • Experiment • Manipulated (Independent) Variable = _______ • Responding (Dependent) Variable = _______ • Experimental (Variable) Group = _______ • Control Group = _______ A B

6. Redi’s Experiment • Results: (write the results here) • Conclusion: (write your conclusion here) A B

7. Experimental Error • The study of life can be difficult, mistakes will happen • Avoidable error • Unavoidable error • There are many sources of error (next to each type put whether they are avoidable or unavoidable) • Disease = _______ • unpredictable behavior = _______ • Death = _______ • human error = _______ • Measuring mistakes = _______ • Not following instructions = _______

8. Structure of DNA • Question/Problem (Q/P) • What is the structure of DNA? • Hypothesis • Watson and Crick had many hypotheses (most of which were wrong) before finally getting it right • Experiment • Many scientists made models and ran experiments testing each hypothesis

9. Structure of DNA • Results • Rosalind Franklin (took a picture) • X-Ray Diffraction Image of DNA • Conclusion • DNA is a double helix