Introduction to Science for Biology Students

1. Introduction to Science for Biology Students Measurement The Scientific Method Graphing

2. Lab Equipment • Graduated Cylinder • Measures Volume • Place on table • Eye Level!! • Read at bottom of curve (meniscus)

3. Beaker • Measures volume • Not as accurate

4. Flask • Measures volume • Not as accurate • Good for mixing

5. Balance • Measures mass • Uses grams • Must “zero” it

6. Ruler • Use CENTIMETERS (cm) or MILLIMETERS (mm) • There are 10 millimeters in every centimeter cm mm

7. The Scientific Method

8. *BREAK* • Problem: I’m cold. • Think of some questions that you might ask me in order to solve my problem.

9. What is the Scientific Method? • A step-by-step way to solve problems Steps: 1. State the Problem 2. Do Research 3. Make a Hypothesis 4. Conduct an Experiment 5. Collect and Measure Data 6. Analyze Data 7. Make a Conclusion

10. 1. State the Problem • The question you are trying to answer • Based on observations you have made • Observations are made by using your senses (sight, sound, touch, etc.) • Observations are facts! • Inferences are opinions, or assumptions, based on your observations

11. Observations vs. Inferences

12. 1. State the Problem • Usually the problem is written as a question • Ex: What affect does caffeine have on your heart rate?

13. 2. Do Research • Examples of Research: • Newspaper article • TV program • Ask an expert • “Google” It

14. 3. Make a Hypothesis • States the expected answer to the problem • What do you think the experiment will show? • Must be able to be tested! • Written in an “If…. Then…” format If you drink a soda with caffeine, then your heart rate will be higher than if you drink a soda without caffeine.

15. 4. Perform an Experiment • The procedure used to test your hypothesis • Hypothesis: If you drink a soda with caffeine, then your heart rate will be higher than if you drink a soda without caffeine. • Your experiment needs to have: • Sodas with caffeine • Sodas without caffeine • People to drink the soda and measure their heart rate

16. In an experiment, you test one variable at a time • A variable is something that changes Independent Variables (IV) – what YOU change on purpose; is known before the experiment Dependent Variable (DV) – what you measure in the experiment; is NOT known before the experiment Controls: a variable that you keep the same throughout the experiment

17. Variables • In our experiment, we have: • Sodas with caffeine • Sodas without caffeine • People to drink the soda and measure their heart rate • What is the Independent Variable? • What is the Dependent Variable? • What are some controls?

18. Answers.. • IV = caffeine • DV = heart rate • Controls = same amount of soda, same age people, possibly same gender, same amount of time, or same person

19. 5. Collect and Measure Data • There are two types of data: • Quantitative = numbers • Qualitative = descriptions • What type of data would… be… • The plant is green • The plant is 2cm tall

20. 6. Analyze Data • Once you have measured your data, you can arrange it in graphs or tables - This will allow you to see any trends in your data Heart rate Caffeine No Caffeine

21. Graphs • There are 3 types of graphs: • Line = shows information over TIME • Bar = shows ONE TIME information • Circle/Pie = shows percentages or parts of a whole

22. 7. Form a Conclusion • You summarize what you discovered in your experiment • You state whether your hypothesis was correct or incorrect • Written in complete sentences! • Ex: A person’s heart rate is higher after drinking a soda containing caffeine than after drinking a soda that does not contain caffeine.