Biology Refresher: Introduction

Scientific Method: A logical problem-solving approach used by biologists and many other scientists.

The scientific method has five basic steps, plus one feedback step:

1. Make an observation.
2. Ask a question.
3. Form a hypothesis, or testable explanation.
4. Make a prediction based on the hypothesis.
5. Test the prediction.
6. Use the results to make new hypotheses or predictions.

Scientists test their hypotheses using controlled experiments. A controlled experiment is a scientific test done under controlled conditions, meaning that just one factor is changed at a time, while all others are kept constant. 
     - Independent Variable: The variable that is changed in the
      experiment. There can only be one.
     - Dependent Variable: The response that is measured to see if
      the independent variable had an effect. The "data". 
     - Experimental Group: The group that is exposed to the
      independent variable in an experiment.
     - Control Group: The group treated just like the experimental
      group EXCEPT they are not exposed to the independent
      variable. The control group provides a baseline that lets
      researchers see if the independent variable has an effect.

Homeostasis: From the Greek words for "same" and "steady," refers to any process that living things use to actively maintain fairly stable conditions necessary for survival. 

An example of homeostasis is the maintenance of body temperature at 37 degrees Celsius.