This document introduces key levels of biological organization from subatomic particles to ecosystems. It discusses the characteristics of living things including being complex, made of cells, obtaining energy and materials, responding to stimuli, growing, reproducing, and evolving over time. The scientific method and development of scientific theories are also outlined. Evolution is presented as the unifying theory of biology, with species adapting or going extinct based on environmental changes over millions of years.

1. Introduction to Life on Earth

2. Levels of Biological Organization I Subatomic Electron Neutron Proton Nitrogen Carbon Hydrogen Oxygen DNA Glucose Water Nucleus Chloroplast Mitochondrion Nerve Cell Atomic Molecular Organelle Cellular O H H CH 2 OH

3. Levels of Biological Organization II Tissue Nervous Tissue Brain Nervous System Pronghorn Antelope Organ (Organ) System Organism

4. Levels of Biological Organization III Population Herd of Pronghorns Hawk Water Earth’s surface Community Ecosystem Biosphere Pronghorns Hawk Grass Pronghorns Snake Bushes Soil Air Snake

5. Principles Underlying All Science All events can be attributed to natural causes Explanations don’t invoke deity (sorry creationists) But should not specifically exclude deity (since we can’t prove it either way) Natural laws apply at all places and all times People perceive events in similar ways

10. The Scientific Method Make observation (something unexpected happens) Propose hypothesis Potential explanation for observation Must lead to “if/then” predictions Design & execute experiment Controlled test of predictions Designed to challenge hypothesis Draw conclusion (supported or not)

11. Scientific Theories A general statement about how things operate Derived through inductive reasoning Has survived thorough challenges Never permanent or final “truth” Always provisional (tentative) Always subject to change or replacement Used to propose hypotheses ( deductive reasoning )

12. Evolution: Unifying Theories of Biology All species evolved from previous species Theories of origin that emerged from inductive reasoning Evolutionary theory emerges from data (true science) Creationism imposes itself on data (not science but doctrine of faith) Extremely vital web linking all biological information

13. When environment changes: Species must adapt to new conditions Some can’t and go extinct Dinosaurs Experienced changes 65 mya Were unable to adapt fast enough Globally extinct Changing Conditions

14. Characteristics of Living Things Complex, organized & made of cells Must get materials & energy Homeostasis maintains internal conditions Growth Respond to stimuli Reproduce themselves Capacity to evolve

15. Salt; Organized but simple Oceans; Complex but unorganized Water flea; Organized and complex Cells are the basic unit of organization in living things Characteristics: 1. Complex, Organized, Cells

16. Characteristics: 2. Respond to Stimuli Changes in internal environment Temperature Water level Blood sugar level Changes in external environment Seek food and water Avoid bitterness Plants grow toward light

17. Characteristics: 3. Homeostasis Organized systems disintegrate Preventing disintegration requires energy Homeostasis means “staying the same” Sweating when hot; shivering when cold Thirsting when water is low

18. Characteristics: 4. Acquire Materials and Energy Homeostasis requires energy Opposes natural trend to disintegration Obtained from external source Homeostasis requires physical repair Parts break down New materials required for repair Food supplies material and energy

19. Characteristics: 5. Growth Violates homeostasis Homeostasis “staying the same” Growth = homeostasis plus extra Organism grows in size/mass Must acquire more than needed for homeostasis Genetically programmed Timing Size Shape

20. Characteristics: 6. Reproduction Reproduce themselves in kind (heredity) Perpetuation of parents’ genetics Genetic info stored in DNA chemical Variation Offspring similar to both parents Offspring different from either parent Simple code with complex error correction system

21. Genetic composition of population changes (evolves) Differential survival (natural selection) “Selects” advantageous adaptations The more time, the more change Eventually become much different Characteristics: 7. Evolution DNA

22. Made of Cells (well, at least 1) Reproduce Obtain/Use Energy Respond to Environment Grow/Develop Mr. D’s Characteristics of Life

23. Categorizing the Diversity of Life I Domains Bacteria & Archaea Prokaryotic Mostly unicellular Domain Eukarya is eukaryotic And other organelles Cells with distinct membrane-bound nucleus

24. Categorizing the Diversity of Life II Kingdom Protista unicellular Kingdom Fungi multicellular, cell wall, heterotroph Kingdom Plantae multicellular, cell wall, autotroph Kingdom Animalia multicellular, heterotroph, no cell wall

25. Variations in Energy Acquisition Plantae Capture light energy Use to make food from carbon dioxide Photosynthetic autotrophs Most others: Eat other organisms to get food Some absorb particles Others ingest bites Heterotrophs

26. The End