UNIT ONE: Habits of Mind

1. UNIT ONE:Habits of Mind

2. How scientists work • No matter what types of problems are being studied, scientists use the same problem-solving steps called the scientific method. • The scientific method is • A logical and systematic approach or process to problem-solving. • An organized way of using evidence to learn about the natural world.

3. Listing the steps • Make an observation. • Define the problem. • Research the problem. • State the hypothesis. • Experiment to test the hypothesis. • Collect and record data. • Analyze the data. • Draw conclusions. • Report results.

4. Question Scientific Method An Overview What does the scientist want to learn more about? First Then Research Gathering of information Next Hypothesis An “Educated” guess of an answer to the question Then Question: What will happen to the magnesium metal if I drop hydrochloric acid into the test tube? Procedure/ Method Written and carefully followed step-by-step experiment designed to test the hypothesis Next Data Information collected during the experiment And And Observations Written description of what was noticed during the experiment Finally Conclusion Was the hypothesis correct or incorrect?

5. Scientific Method Ask Question Do Background Research Think! Try Again Construct Hypothesis Test with an Experiment Analyze Results Draw Conclusion Hypothesis is True Hypothesis is False or Partially True Report Results

6. Redi’s experiment on Spontaneous Generation • Aristotle proposed that living things can be generated from non-living things, and his theory is called Spontaneous Generation in 322 BC. • People accepted the idea. • Francesco Redi disagreed in 1668. He was trying to disprove the idea of Spontaneous Generation using fruit flies. • WAIT…people believed this for 1668 + 322 years!

7. Make an observation • Maggots occur on meat after a few days.

8. Define the problem. • How did the maggots get on the meat?

9. Research the problem. • Redi observed that maggots appeared on the meat after a few days. • He believed that flies landed on the meat, laid eggs, and the eggs hatched.

10. State the hypothesis • Flies produce maggots.

11. Experiment to test the hypothesis • Redi set up a controlled experiment. Others have used his experiment as a model for setting up their own experiments for many years. Experimental Group Control Group

12. Important vocabulary & Concepts • Experimental group: Jars with meat and a gauze cover • Manipulated variable: gauze covering the jar (ONLY ONE) • Dependent variable: whether maggots appear or not (RESULT) • Control Group: used as a standard of comparison • Jars with meat and no cover • Control variables: same jars, same type of meat, same location, same temperature, same amount of time (MANY)

13. Collect Data • Redi recorded the size jar, type of meat, amount of meat, location of meat, temperature of room, time passed, type of gauze used, changes in meat each day, and when/if maggots appeared. • Maggots only appeared on the meat in the uncovered jars after a few days. No maggots appeared on the meat in the covered jars. • Types of Data: • Quantitative: involves numbers; often graphed • Qualitative: does not involve numbers

14. Draw conclusions • Redireviewed his hypothesis: Flies produce maggots. • He accepted the hypothesis because of the data. • Flies must have laid eggs that are too small to be seen. • Flies could not get to the covered meat to lay their eggs. • Maggots did not spontaneously generate on the meat. • EVIDENCE was necessary to disprove Aristotle’s claim. Data IS evidence.

15. Determine limitations • Redilooked over his work carefully. He tried to identify mistakes in his experiment. Could there be another explanation for his results? • He looked for ways to improve his experiment. • He decided if it was necessary to repeat the experiment with the improvements.

16. Report results • When Redi was satisfied with his results, he wrote a report of the experiment outlining all of the information that we’ve discussed. • He published that report in 1668 in a book. • Other scientists repeated his experiment to check his work, and finally the theory of spontaneous generation was disproved.

17. Review of experimental variable vocabulary • Variables - Factors that can be changed • Controlled Variables - all the variables that remain constant • Independent Variable - (also called the Manipulated Variable) - factor in an experiment that a scientist purposely changes • Dependent Variable- (also called the Responding Variable) - the outcome or results, factor in an experiment that may change because of the manipulated variable….what a scientist wants to measure or observe • Graphing Rule: Graph the dependent variable on the Y-axis. The independent variable goes on the X-axis.

18. OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Covered jars Uncoveredjars Controlled Variables: jars, type of meat, location, temperature, time Several days pass Manipulated Variables: gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

19. Gathering quantitative data • Usually quantitative data is measured with an instrument in the lab. • Scientists use the metric system units.

20. Metric system prefixes & conversions • The metric system is based upon powers of ten. • Prefixes are added to the base units to make larger or smaller units. • Example: milli, kilo, or deci • Since our number system is also based on powers of ten, converting from one metric prefix to another is as simple as moving a decimal. • Memory device: King Henry died by drinking chocolate milk.

21. Metric system prefixes & conversions • Conversion examples • Convert 145.8 cm to mm. • 1458 mm • Convert 3.4 kg to dg. • 34,000 dg • Convert 13,499 mL to hL. • 0.13499 hL • For homework tonight, complete the metric mania worksheet.

22. Characteristics of Living Things • Biology is the study of life! • Are Flames Alive? • All living things have 8 characteristics in common. • Made of one or more cells • Displays organization • Grows & develops (increase in mass & gains new abilities) • Reproduces • Responds to stimuli (ex. heat, light, weather) • Requires energy • Maintains homeostasis (stable internal conditions) • Adaptations evolve over time (help species survive)

23. Displays organization • Levels of Organization • Organisms • Organ systems • Organs • Tissues • Cells • Molecules • Atoms