Welcome to Biol 178 Principles of Biology Course goals Course information Text Grading Syllabus Lab Chapter Organization

Concept Outline Text Concept Review Test Your Understanding Test Your Visual Understanding Chapter Organization

Lecture Outline  Definition of Life  Properties of Life  Hierarchical Organization  Unifying Themes of Science  Scientific Method

What is Biology? oStudy of life oSearch for order in the natural world oDiscovery of new relationships oLearn working rules that allow life to exist

Properties of Life  Cellular organization  Order  Sensitivity  Growth, development, and reproduction  Genetic system  DNA  Energy utilization  Evolutionary adaptation  Homeostasis

Hierarchical Organization of Life 1.Population Level 2.Organism Level 3.Cell Level

Life Levels of Organization Populations…Among Organisms 1.Biosphere 2.Ecosystem 3.Community 4.Population

Life Levels of Organization Within Organisms 1.Organ systems 2.Organs 3.Tissues 4.Cells

Life Levels of Organization Within Cells 1.Organelles 2.Macromolecules 3.Molecules & Atoms

Life Levels of Organization 1.Among organisms 2.Within Organisms 3.Within Cells

Consequences of Hierarchical organization Emergent properties New properties arise at each higher level Make life difficult to define

Unifying Themes of Science 1. Cell theory All living organisms are made of cells, and all living cells come from other living cells. 2. Molecular basis of inheritance DNA encodes genes Genes make-up & control living organisms.

Unifying Themes of Science 3. Evolutionary change Life-forms have evolved varying characteristics to adapt to varied environments. 4. Evolutionary conservation Some characteristics of earlier organisms are preserved and passed on to future generations.

Summary: Unifying Themes of Science 1. Cell theory 2. Molecular basis of inheritance 3. Evolutionary change 4. Evolutionary conservation

Scientific Inquiry – How is Science Done? Discovery Science Observing Measuring Hypothesis-based Science Scientific Method Proposing & Testing hypotheses Inductive & deductive logic

Reasoning Deductive reasoning Apply general principles to predict specific results Inductive reasoning Use specific observations to construct general principles

How Science Is Done 1. Observation: Begins science 2. Hypothesis: accounts for observations Educated guess Inductive Reasoning  Generalization 3. Prediction: Allows test of hypothesis validity Deductive Reasoning  specific outcome 4. Experiment: Tests hypothesis validity 5. Controlled experiment: One variable Control

How Science Is Done

Limitations of Science Hypothesis can NOT be proven true Truth Table HypothesisPrediction True False False or True

Limitations of Science Science does not prove hypotheses are true. Science proves that some hypotheses are not true. Hypotheses not proven false are conditionally accepted.

Hypotheses, Theories & Laws  Hypothesis a tentative explanation.  Scientific Theory Accepted explanation. Supported by experimental evidence. Solid ground of science. A well-supported hypothesis.  Scientific Law Scientific knowledge accepted as true. An extremely well-supported hypothesis.

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