Ap bio lecture ch1 a view of life


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  • Biology, 9th ed,Sylvia Mader A View of Life Slide # Chapter 01
  • Biology, 9th ed,Sylvia Mader A View of Life Slide # Chapter 01
  • Biology, 9th ed,Sylvia Mader A View of Life Slide # Chapter 01
  • Biology, 9th ed,Sylvia Mader A View of Life Slide # Chapter 01
  • Ap bio lecture ch1 a view of life

    1. 1. A View of Life WarmUp Questions3.What are the eleven levels of biological organization in order from largest tosmallest?5.Name 4 characteristics of life.7.Can you differentiate between inductive and deductive reasoning?
    2. 2. A View of LifeThe phenomenon we call… LIFE
    3. 3. Chapter 01A View of Life
    4. 4. A View of Life Biologists use various forms of inquiry to explore life At the heart of science is inquiry ◦ A search for information and explanation, often focusing on specific questions Biology blends two main processes of scientific inquiry ◦ Discovery science ◦ Hypothesis-based science
    5. 5. A View of Life◦ Describes natural structures and processes as accurately as possible through careful observation and analysis of data
    6. 6. A View of Life Data ◦ Are recorded observations ◦ Can be quantitative or qualitative Figure 1.24
    7. 7. A View of Life In inductive reasoning ◦ Scientists derive generalizations based on a large number of specific observations
    8. 8. A View of Life In science, inquiry that asks specific questions ◦ Usually involves the proposing and testing of hypothetical explanations, or hypotheses
    9. 9. A View of Life In science, a hypothesis ◦ Is a tentative answer to a well-framed question, an explanation on trial ◦ Makes predictions that can be tested
    10. 10. A View of Life We use simple hypotheses ALL THE TIME Observations Questions Hypothesis # 1: Hypothesis # 2: Dead batteries Burnt-out bulb Prediction: Prediction: Replacing batteries Replacing bulb will fix problem will fix problem Test prediction Test predictionFigure 1.25 Test falsifies hypothesis Test does not falsify hypothesis
    11. 11. A View of Life In deductive reasoning ◦ The logic flows from the general to the specific If a hypothesis is correct ◦ Then we can expect a particular outcome
    12. 12. A View of Life A scientific hypothesis must have two important qualities ◦ It must be testable ◦ It must be falsifiable
    13. 13. A View of Life The scientific method ◦ Is an idealized process of inquiry Very few scientific inquiries ◦ Adhere to the “textbook” scientific method
    14. 14. A View of Life In mimicry ◦ A harmless species resembles a harmful species Flower fly (non-stinging) Honeybee (stinging) Figure 1.26
    15. 15. A View of Life In this case study ◦ Mimicry in king snakes is examined ◦ The hypothesis predicts that predators in non–coral snake areas will attack king snakes more frequently than will predators that live where coral snakes are present Scarlet king snake Key Range of scarlet king snake Range of eastern color snake North Carolina South Carolina Eastern coral snake Figure 1.27 Scarlet king snake
    16. 16. A View of Life To test this mimicry hypothesis ◦ Researchers made hundreds of artificial snakes, an experimental group resembling king snakes and a control group of plain (a) Artificial king snake brown snakes Figure 1.28 (b) Brown artificial snake that has been attacked
    17. 17. A View of Life After a given period of time Key Key % of attacks on artificial king snakes ◦ The researchers % of attacks on brown artificial snakes collected data that fit a Field site with artificial snakes key prediction In areas where coral snakes 17% were absent, most attacks 83% were on artificial king snakes X North XX X XX Carolina X South XX Carolina X X X XX 16% 84% In areas where coral snakes were present, most attacks were on brown Figure 1.29 artificial snakes
    18. 18. A View of Life Experiments must be designed to test ◦ The effect of one variable by testing control groups and experimental groups in a way that cancels the effects of unwanted variables
    19. 19. A View of Life Science cannot address supernatural phenomena ◦ Because hypotheses must be testable and falsifiable and experimental results must be repeatable
    20. 20. A View of Life A scientific theory ◦ Is broad in scope ◦ Generates new hypotheses ◦ Is supported by a large body of evidence
    21. 21. A View of Life Defining Life ◦ Emergent Properties ◦ Organized ◦ Materials and Energy ◦ Response ◦ Reproduce and Develop ◦ Adaptations and Natural Selection Biosphere Organization ◦ Human Population ◦ Biodiversity Classification The Scientific Method 21
    22. 22. A View of Life Living things vs. nonliving objects: ◦ Comprised of the same chemical elements ◦ Obey the same physical and chemical laws The cell is the smallest, most basic unit of all life ◦ Familiar organisms are multicellular ◦ Some cells independent – single-celled organisms 22
    23. 23. Defining Life
    24. 24. A View of Life Emergent Properties – Biological organization ◦ Levels range from extreme micro to global ◦ Each level up:  More complex than the preceding level  Properties:  A superset of preceding level’s properties emerge from interactions between components 24
    25. 25. Levels of Biological Organization
    26. 26. Living Things:1. Demonstrate Order2. Self-regulation3. Growth and Development
    27. 27. A View of Life Energy - the capacity to do work ◦ The sun:  Ultimate source of energy for nearly all life on Earth  Drives photosynthesis ◦ Metabolism - all the chemical reactions in a cell  Homeostasis - Maintenance of internal conditions within certain boundaries 27
    28. 28. AcquiringNutrients
    29. 29. A View of Life Living things detect changes in environment Response often involves movement ◦ Vulture can detect and find carrion a mile away ◦ Monarch butterfly senses fall and migrates south ◦ Microroganisms follow light or chemicals ◦ Even leaves of plants follow sun Responses collectively constitute behavior 29
    30. 30. A View of Life Organisms live and die Must reproduce to maintain population Multicellular organisms: ◦ Begins with union of sperm and egg ◦ Developmental instructions encoded in genes  Composed of DNA  Long spiral molecule in chromosomes 30
    31. 31. Rockhopper Penguins & Offspring
    32. 32. A View of Life Adaptation ◦ Any modification that makes an organism more suited to its way of life ◦ Organisms, become modified over time ◦ However, organisms very similar at basic level  Suggests living things descended from same ancestor  Descent with modification - Evolution  Caused by natural selection 32
    33. 33. A View of Life Population - Members of a species within an area Community - A local collection of interacting populations Ecosystem - The communities in an area considered with their physical environment  How chemicals are cycled and re-used by organisms  How energy flows, from photosynthetic plants to top predators 33
    34. 34. Terrestrial Ecosystems: A Grassland
    35. 35. MarineEcosystems:A Coral Reef
    36. 36. A View of Life Ecosystems negatively impacted by human populations ◦ Destroyed for agriculture, housing, industry, etc. ◦ Degraded and destabilized by pollution However, humans depend upon healthy ecosystems for ◦ Food ◦ Medicines ◦ Raw materials ◦ Other ecosystem processes 36
    37. 37. A View of Life Biodiversity: ◦ The total number of species (est. 15 million) ◦ The variability of their genes ◦ The ecosystems in which they live Extinction: ◦ The death of the last member of a species ◦ Estimates of 400 species/day lost worldwide 37
    38. 38. A View of Life Taxonomy: ◦ The rules for identifying and classifying organisms ◦ Hierarchical levels (taxa) based on hypothesized evolutionary relationships ◦ Levels are, from least inclusive to most inclusive:  Species, genus, family, order, class, phylum, kingdom, and domain  A level usually includes more species than the level below it, and fewer species than the one above it 38
    39. 39. A View of Life 39Taxon Human CornDomain Eukarya EukaryaKingdom Animalia PlantaePhylum Chordata AnthophytaClass Mammalia LiliopsidaOrder Primates CommelinalesFamily Hominidae PoacaeGenus Homo ZeaSpecies H. sapiens Z. mays
    40. 40. A View of Life Bacteria ◦ Microscopic unicellular prokaryotes Archaea ◦ Bacteria-like unicellular prokaryotes ◦ Extreme aquatic environments Eukarya ◦ Eukaryotes – Familiar organisms 40
    41. 41. Domains:The Archaea
    42. 42. Domains: TheBacteria
    43. 43. A View of Life Archaea – Kingdoms still being worked out Bacteria - Kingdoms still being worked out Eukarya ◦ Kingdom Protista ◦ Kingdom Fungi ◦ Kingdom Plantae ◦ Kingdom Animalia 43
    44. 44. Domains:The Eukaryote Kindoms
    45. 45. A View of Life Binomial nomenclature (two-word namess) Universal Latin-based ◦ First word represents genus of organism ◦ Second word is specific epithet of a species within the genus ◦ Always Italicized asa Genus species (Homo sapiens) ◦ Genus may occur alone (Homo), but not specific epithet 45
    46. 46. A View of Life Begins with observation ◦ Scientists use their five senses ◦ Instruments can extend the range of senses Hypothesis ◦ A tentative explanation for what was observed ◦ Developed through inductively reasoning from specific to general 46
    47. 47. The Scientific Method:A Flow Diagram
    48. 48. A View of Life Experimentation ◦ Purpose is to challenge the hypothesis ◦ Designed through deductively reasoning from general to specific ◦ Often divides subjects into a control group and an experimental group ◦ Predicts how groups should differ if hypothesis is valid  If prediction happens, hypothesis is unchallenged  If not, hypothesis is unsupportable 48
    49. 49. A View of Life Results ◦ Observable, objective results from an experiment ◦ Strength of the data expressed in probabilities ◦ The probability that random variation could have caused the results  Low probability (less than 5%) is good  Higher probabilities make it difficult to dismiss random chance as the sole cause of the results 49
    50. 50. A View of Life The results are analyzed and interpreted Conclusions are what the scientist thinks caused the results Findings must be reported in scientific journals Peers review the findings and the conclusions Other scientists then attempt to duplicate or dismiss the published findings 50
    51. 51. A View of Life Scientific Theory: ◦ Joins together two or more related hypotheses ◦ Supported by broad range of observations, experiments, and data Scientific Principle / Law: ◦ Widely accepted set of theories ◦ No serious challenges to validity 51
    52. 52. A View of Life Experimental (Independent) variable ◦ Applied one way to experimental group ◦ Applied a different way to control group Response (dependent) variable ◦ Variable that is measured to generate data ◦ Expected to yield different results in control versus experimental groups 52
    53. 53. A View of Life Observations: ◦ Nitrate fertilizers boost grain crops, but may damage soils ◦ When grain crops are rotated with pigeon pea it adds natural nitrogen Hypothesis: ◦ Pigeon pea rotation will boost crop production as much as nitrates ◦ Pigeon pea rotation will NOT damage soils 53
    54. 54. RootNodules
    55. 55. A View of Life Experimental Design ◦ Control Group  Winter wheat planted in pots without fertilizer ◦ Experimental Groups  1-Winter wheat planted in pots with 45 kg/ha nitrate  2-Winter wheat planted in pots with 90 kg/ha nitrate  3-Winter wheat planted in pots that had grown a crop of pigeon peas ◦ All groups treated identically except for above 55
    56. 56. Crop Rotation Study
    57. 57. A View of Life Experimental Prediction: ◦ Wheat production following pigeon pea rotation will be equal or better than following nitrate fertilizer Results ◦ 45 kg/ha produced slightly better than controls ◦ 90 kg/ha produced nearly twice as much as controls ◦ Pigeon pea rotation did not produce as much as the controls 57
    58. 58. A View of Life Conclusion ◦ Research hypothesis was not supported by results ◦ However, research hypothesis was not proven false by negative results Revised experiment ◦ Grow wheat in same pots for several generations ◦ Look for soil damage in nitrate pots and improved production in pigeon pea pots 58
    59. 59. A View of Life Results ◦ After second year:  Production following nitrates declined  Production following pigeon pea rotation was greatest of all ◦ After third year  Pigeon pea rotation produced 4X as much as controls Revised conclusions ◦ Research hypothesis supported ◦ Pigeon pea rotation should be recommended over nitrates 59
    60. 60. A Field Study
    61. 61. A View of Life Defining Life - Emergent Properties ◦ Materials and Energy ◦ Reproduction and Development ◦ Adaptations and Natural Selection Biosphere Organization ◦ Human Population ◦ Biodiversity Classification The Scientific Method 61
    62. 62. Ending Slide Chapter 01A View of Life