Exploring Life Science Chapter 1

Science The goal of science is to understand the world around us. Scientists use special methods to determine truths about nature called facts. Scientists observe, question, form a hypothesis, gather data and make conclusions.

Theories vs Laws in Science A scientific theory is a time-tested concept that makes useful and dependable predictions about the natural world. Theories must be tested many times and are revised as more information is collected. It could become a law over time.

Branches of Science There are many branches of science, however the three main branches are: Physical Science, Earth Science and Life Science Physical science studies the physical world. Earth science studies the earth. Life science studies living things.

Life Science Life science deals with living things and their relationship to one another and their environment. Life science can be divided into more specialized branches. Zoology: study of animals Botany: study of plants Ecology: study of the relationships between living things and their environment Microbiology: study of microorganisms Anatomy & Physiology: study of organism parts & they way they work.

The Scientific Method The scientific method is a systematic approach to problem solving. The steps of the scientific method are: Observations that indicate a problem needs solving Gathering Information on the Problem to help make a research question Forming a Hypothesis Performing Controlled Experiments to Test the Hypothesis Recording and Analyzing Data Stating a Conclusion, Evaluating the experiment design Repeating the Work

Variables Each experiment is based on changing only one variable (the independent or manipulated variable) Data is collected on dependent variable. Both (independent & dependent) must be included in the research question which defines the experiment. Controlled variables Are those factors that need to remain the same in each trial (to ensure a fair test) We should define the controlled variable and add detail as to how it will be controlled (an operational definition)

Forming a Hypothesis A hypothesis is a suggested solution to the problem, based upon research & observations. A hypothesis is formed after the important information about the problem has been reviewed. The experiment is designed around the hypothesis, and data collected directly is related to it.

Performing an Experiment An experiment is an activity that test the hypothesis. It is very important to record procedures and results of the experiment. Only one factor or variable can be tested at a time. A control is also used in experiments. It is identical to the experiment, except the changed variable is left out. (this isn’t the same as controlled variables)

Recording and Analyzing Data During and after an experiment all data is recorded and analyzed. Data includes observations such as measurements (quanititative) and observations (qualitative). Often graphs or tables are used to analyze data.

Stating a Conclusion & Evaluation the Experiment After data is analyzed, scientists come to a conclusion. Conclusions either find the hypothesis was supported or the hypothesis was disproved. They then evaluate their data – how accurate & reliable? Were there problems that needed fixed? What were the strengths? Should it be repeated?

Repeating the Work Experiments must be repeated several times to make sure the same conclusion is always reached and to check to see if the results are accurate. This is peer review and some is done before publication, and more review is completed after publication.