Bell Work  Answer the questions on your bell work (it looks like this:  What are the steps to the Scientific Method?  Which step do you think is the most important and why?  How can you stay safe in the lab?  Why do you think lab safety is so important?

One of the most important parts of the scientific method

Review the Scientific Method  Obsevation  Hypothesis  Experimental Design  Analysis  Conclusions

Hypothesis  The hypothesis should always be an If... then statement. (If I do this, then this will happen)  The if part of the statement should be your independent variable  The then part of the statement should be your dependent variable or state what you are measuring.  The hypothesis is what drives the entire experiment, so it is the most important part!!!

Controls  When creating an experiment you must have a control.  A control is a way to compare your results to the experimental group.  Controls should simulate a typical response.

Placebo  A placebo is a substance given to the control group that should have no therapeutic effect  For example, commercials on the radio ask people to volunteer to try a new acne medication. What they say in the fine print is that half the participants will really just taking a sugar pill, not the acne medication, so they have a basis for comparison.  Why do you think using a placebo is beneficial?  It shows if there is a placebo effect (when the acne disappears just because the person believes it will because they think they are receiving a treatment).

Variables  A variable is the thing that is changing in the experiment.  You should only change one variable at a time.  The variable that you deliberately changed is the manipulated or independent variable.  The variable that changes as a response to that variable is the responding or dependent variable.

Redi’s Experiment  Observation – flies land on meat that is uncovered and then maggots appear.  Hypothesis – Flies produce maggots  Procedure – Redi put a piece of meat in two jars. He covered one in cheesecloth.  Analysis – The meat in the covered jar did not develop maggots, but the uncovered jar did.  Conclusion – There is no such thing as spontaneous generation.

What was the...  Control  Why did he need the control?  Dependent variable  Independent variable  Constants

Theories  Not all hypothesis can be tested...  When this occurs observations must be interpreted to create and support a theory.  Hypotheses need to be built upon by many scientists and a lot of ‘proof’ needs to be found before a hypothesis can be considered a theory.

Publishing and Repeating  Redi published his experiment  Three scientists reproduced his experiment in different ways  Needham – tried to disprove Redi  Spallazani – disproved Needham  Pasteur – used Spallazani’s experiment to create the process of pasteurization.

‘Publishing’ Your Experiments  You will have to complete lab write-ups in this class.  These write-ups need to follow the standard format for any science writing:  Theory – Background information about the topics in the lab.  Results – This is the raw data without any interpretation or explanation.  Conclusions – This is where you explain your results and discuss an errors or future endeavors.

Theory  The best way to write good theory is to start with a good hypothesis.  Pick out the key words in your hypothesis, and these are the key concepts that should be explained in your theory.  The theory section should be written before you finish collecting your results.  It should include your hypothesis and explain the science behind why you chose your hypothesis

Results  This section should include  Data tables with labels  Some type of representation of the data (graph, picture, calculations, etc.)  Caption explaining each table or graph.  There should be absolutely no ‘because’. This section does not explain why you got the results you did.

Conclusion  The conclusion needs to include  Explanation of results with scientific fact to back it up.  Errors that may have occurred during the lab.  There are always possible errors!  Errors should never make you look careless. Never use miscalculations or errors of measurement or blame other classmates. Try to choose non-human errors whenever possible.

Dive Response  When marine mammals dive under water their body responds. This also happens to humans to a slightly lesser degree.  Our heart rates slow down by about 25%  Cappillaries close off to our extremities leaving more oxygen to be used for our heart and brains.  This optimized respiration occurs to allow us (and other marine mammals to stay underwater longer.

What Causes This?