THE STUDY OF LIFE Biology

Science is a gas, it rocks, it rules, its da bomb Two types of science studied at Nashua High school are life sciences and physical sciences: Biology is a graduation requirement and a prerequisite for other life science courses. Life SciencesPhysical Sciences Biology Anatomy and physiology Biotechnology Environmental science Zoology Plant science Physical Science Physics Chemistry Aerospace science Astronomy Biotechnology

Theories and Laws are not “beliefs” Biology, like all sciences investigates the natural world and uses data collected to try to explain natural events, describe natural phenomena, and make useful predictions Scientific TheoriesScientific Laws Explanations of the “whys and hows” of natural phenomena Derived from much data collected from repeatable experiments Falsifiable Ex: Cell theory Describe natural phenomena Often modeled with mathematical formulas that represent predictable relationships Ex:Newton’s Universal Law of Gravitation

A Law you can’t break

A falsifiable theory Cell Theory: All life forms are made from one or more cells. Cells only arise from pre-existing cells. The cell is the smallest form of life.

Scientific Habits of Mind Observant-details matter! Curious- question why and how things happen in nature Rational-make inferences by connecting prior knowledge and experience to new situations in a logical way. Skeptical-Scientific people question their own inferences and other’s continually to assess value of data. Open minded-Scientists always try to understand other’s interpretations of data and are always on the lookout for new ideas and data to incorporate into his or her knowledge base. Ethical-we have a responsibility to consider the effects of our work and to be honest in data reporting and analysis.

Knowledge is a process Science does not fail when new information proves old ideas to be wrong, it is demonstrating growth and advancement. Scientific Method: Observe, question, hypothesize, experiment, analyze, conclude, retest, analyze, revise (hypothesis or experiment), retest, analyze revise, retest………..

Variables in an experiment Variable: something that varies or changes or can be changed in a situation. Controlled variable: what the scientist controls so that is does not affect the experiment Manipulated variable: what the scientist changes in one of his or her test groups in order to cause a change to occur. Responding variable: what changes because of the manipulated variable, depending on whether or not the test group has been manipulated.

Redi’s experiment 1668

Needham’s disagreed with Redi… 1745

Spallanzani Louis Pasteur 1864

Louis Pasteur Contributed to the development of Germ Theory, which explains what causes infection and contamination, before Pasteur doctors didn’t even wash their tool or hands! Developed a boiling process we use to keep milk from spoiling: PASTEURIZATION Developed the first vaccines for rabies and anthrax Discovered anaerobiosis: bacteria that live without air..**The “Pasteur effect” is that fermentation slows in presence of air. Aerobic:with airAnaerobic: without air

Life is cells, but what does life do differently than non-life? Life reproduces Life has a genetic code that all life on earth shares (DNA) Life grows larger and develops in stages Life must obtain energy for chemical reactions and raw materials (matter) for needed life chemicals. (metabolism) Life must perceive and respond to its environment. Life has a different internal environment from its outside environment and must maintain this difference. (homeostasis) As a group life must change over time to survive environmental changes. (Evolution)