UNIT ONE: HABITS OF MIND

 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. HOW SCIENTISTS WORK

1.Make an observation. 2.Define the problem. 3.Research the problem. 4.State the hypothesis. 5.Experiment to test the hypothesis. 6.Collect and record data. 7.Analyze the data. 8.Draw conclusions. 9.Report results. LISTING THE STEPS

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

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

 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 He was trying to disprove the idea of Spontaneous Generation using fruit flies.  WAIT…people believed this for years! REDI’S EXPERIMENT ON SPONTANEOUS GENERATION

 Maggots occur on meat after a few days. MAKE AN OBSERVATION

 How did the maggots get on the meat? DEFINE 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. RESEARCH THE PROBLEM.

 Flies produce maggots. STATE 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. EXPERIMENT TO TEST THE HYPOTHESIS Control Group Experimental Group

 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)  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) IMPORTANT VOCABULARY & CONCEPTS

 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 COLLECT DATA

 Redi reviewed 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. DRAW CONCLUSIONS

 Redi looked 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. DETERMINE LIMITATIONS

 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. REPORT RESULTS

 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. REVIEW OF EXPERIMENTAL VARIABLE VOCABULARY

OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Manipulated Variables: gauze covering that keeps flies away from meat Uncovered jars Covered jars Several days pass Maggots appearNo maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Controlled Variables: jars, type of meat, location, temperature, time

 Usually quantitative data is measured with an instrument in the lab.  Scientists use the metric system units. GATHERING QUANTITATIVE DATA MeasurementEquipment UsedMetric Base Unit LengthMetric ruler or meter stick Meters MassBalanceGram Volume of a liquidGraduated cylinderLiter TimeStopwatch or second hand on clock second

 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. METRIC SYSTEM PREFIXES & CONVERSIONS KiloHectoDecaBASEDeciCentiMilli KhDMeter Liter Gram dcm

 Conversion examples  Convert cm to mm.  1458 mm  Convert 3.4 kg to dg.  34,000 dg  Convert 13,499 mL to hL.  hL  For homework tonight, complete the metric mania worksheet. METRIC SYSTEM PREFIXES & CONVERSIONS KiloHectoDecaBASEDeciCentiMilli KhDMeter Liter Gram dcm

 Biology is the study of life!  Are Flames Alive? Are Flames Alive?  All living things have 8 characteristics in common. 1.Made of one or more cells 2.Displays organization 3.Grows & develops (increase in mass & gains new abilities) 4.Reproduces 5.Responds to stimuli (ex. heat, light, weather) 6.Requires energy 7.Maintains homeostasis (stable internal conditions) 8.Adaptations evolve over time (help species survive) CHARACTERISTICS OF LIVING THINGS

 Levels of Organization  Organisms  Organ systems  Organs  Tissues  Cells  Molecules  Atoms DISPLAYS ORGANIZATION