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

2 What is Biology?  Study of life  Search for order in the natural world  Discovery of new relationships  Learn working rules that allow life to exist

3 Concept Outline Text Interim Summaries Summary Tables Concept Review Self Test Questions Challenge Questions Chapter Organization & Aids to Promote Learning

4 Lecture Outline A view of Life  Characteristics of living organisms Organization of life:  Levels of organization  How to do Science

5 Lecture Outline 1 Reading Assignment: Chapter 1 A view of Life: Characteristics of living organisms A. Cellular organization B. Metabolism C. Homeostasis D. Reproduction E. Heredity F. Adaptability G. Growth H. Response I. Other

6 Levels of Organization Cellular Organization cells organelles molecules atoms The cell is the basic unit of life.

7 Levels of Organization Organismal Level organism organ systems organs tissues

8 Levels of Organization Population Level ecosystem community species population

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

10 Consequences of Hierarchical organization Emergent properties New properties arise at each higher level

11 Unifying Themes of Biology 1. Cells 2. Molecular basis of inheritance - DNA 3. Structure & function are interrelated 4. Evolution produces diversity 5. Evolutionary conservation 6. Life has emergent properties

12 How is science done? Science aims to understand the natural world through observation and reasoning. Science begins with observations, therefore, much of science is purely descriptive. Science uses both deductive and inductive reasoning.

13 The Nature of Science Deductive reasoning uses general principles to make specific predictions. Inductive reasoning uses specific observations to develop general conclusions.

14 The Nature of Science Scientists use a systematic approach to gain understanding of the natural world. -Observation -Hypothesis formation -Prediction -Experimentation -Conclusion

15 The Nature of Science A hypothesis is a possible explanation for an observation. Hypothesis leads to a prediction.

16 The Nature of Science The experiment -tests the hypothesis by testing prediction -must be carefully designed to test only one variable at a time -consists of a test experiment and a control experiment

17 The Nature of Science Prediction  True  Conditionally Accept Hypothesis  False  Reject Hypothesis

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

20 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.

21 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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