Chapter   1 - Concepts and Methods in Biology

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RESOURCES

1. Textbook website:
   1. outline, quiz, and flash cards: select from resources for chapter 1.
2. STARR and TAGGART 9th edition website:
   1. outline, quiz, and flash cards: select from resources for chapter 1.
3. STARR AN TAGGART 10th edition website:
   1. outline, quiz, and flash cards: select from resources for chapter 1.
4. On-Line Biology Book: THE NATURE OF SCIENCE AND BIOLOGY

BIOLOGY - The scientific study of life

CHARACTERISTICS OF LIFE

Characteristics of Life from Risk Hershberger, the Bioactive Site

1. Nothing Lives Without DNA
   1. DNA (deoxyribonucleic acid) - molecule unique to living organisms  
      1. Contains instructions for assembling new cells and/or organisms and for utilizing matter plus energy
      2. Agent of heredity.
      3. Reproduction: life comes only from life; maintains the species
      4. Growth and Development (Fig. 1.3).
2. Nothing Lives Without Energy
   1. Acquisition of Material and Energy
      1. Metabolism
         1. Photosynthesis 
         2. Cellular Respiration
   2. Living Things Respond
      1. Receptors
      2. Movement
      3. Homeostasis 
         • Homeostasis - Rick Hersberger, The Bioactive Site
3. Organization-link to M.J. Farabee, the On-Line Biology Book [Figure 1.5]
   1. Atom - Molecule - Cell - Tissue - Organ - Organism - Population - Community - Ecosystem - Biosphere
   2. Life's Hierarchy from the MIT Hypertextbook
   3. cell - basic unit of life
   4. Ecological organization
      1. population: individuals of one species in a particular area
      2. community: associations of populations (100's-1000's) of species in same area
      3. ecosystem: community plus non-living environment; major natural communities
      4. biosphere: planet Earth - largest ecosystem
   5. Emergent Properties
      1. Properties that emerge as a result of interactions between components. 
         1. New properties emerge with each step up the hierarchy of life's organization.
      2. Emergent properties are characteristic of life and include characteristics such as response to stimuli, homeostasis, heredity, growth, development, etc.
      3. Holism is the principle that a higher level of order cannot be meaningfully explained by looking at the component parts in isolation.
   6. Reductionism is the opposite of holism, the complex can be explained by understanding its components. 
4. Interdependency among Organisms
   1. Energy flow --> trophic interactions [fig. 1-6]
      1. sunlight, producers, consumers, decomposers, inorganic nutrients
      2. one way flow of energy
      3. recycling of nutrients
5. Life's Diversity
   1. Linnaean Taxonomic Hierarchy
   2. Carolus Linnaeus (1707-1778)
      1. hierarchical system: hierarchy of taxonomic ranks 
         • domain, kingdom, phylum, class, order, family, genus, species
         • see this page on classification by Stephen Abedon for some interesting mnemonics
      2. binomial nomenclature
   3. more on classification from the University of Minnesota, General Zoology
   4. biological species concept

Three Domains: Eubacteria, Archaea, Eukarya  

• Procaryotes: The old Kingdom Monera.  Now split into two kingdoms:
  1. Eubacteria from Kimball's Biology Place
  2. Archea from Kimball's Biology Place
• Eucaryotes
  • Protista
  • Fungi
  • Plantae
  • Animalia

SIX Kingdoms [Fig. 1.7]

6. Living Things Reproduce and Develop
   1. Reproduction - Life generating life by making copy similar to self
   2. Heredity - Factors passed on when an organism reproduces
   3. Genes - contain blueprint (DNA) for an organism's organization and metabolism
   4. Mutation - a change in DNA that can be inherited
   5. Inheritance
7. Living Things Have Adaptations
   1. Adaptation
   2. Biston betularia [Figure 1.7] and industrial melanism
      1. observations and experiments
      2. There are some problems with Kettlewell's explanation.  Moths have not been observed resting on limbs.  In his experiment Kettlewell placed moths on limbs.
      3. However, industrial melanism has been observed on different continents and Kettlewell's hypothesis explaining it does agree with the experiments.
      4. Use the CD-rom that comes with the book and see what happens when you try to eat light and dark moths against  different experiments.
   3. Evolution - Change in characteristics of organisms over time

      Evolution is the unifying concept of biology

Evidence of Evolution

• Evidence for Evolution from mj farabee Maracopa
• Evolution from PBS
• Evidence Supporting Biological Evolution from the National Academy of Sciences
• Evolution: Converging Lines of Evidence 
• Evidence for Evolution from Talk Origins

1. Biogeography  
2. Paleontology
   1. Fossils 
   2. History of the Earth (Table 1.1)
      1. Geologic Time from the USGS
      2. Geologic Time Scale from the UCMP
3. Comparative Anatomy
   1. homology
   2. convergent evolution
      1. analogous structures  
   3. vestigial structures
4. Molecular Biology

1. Darwin used artificial selection [fig. 1.7] as a model for natural selection
2. natural selection 1859: Charles Darwin and Alfred Russell Wallace
   1. all individuals vary
   2. most variation is heritable
   3. some traits increase adaptation
   4. competition for limited resources
   5. better adapted are more likely to survive and reproduce (excess reproductive capacity and differential reproduction)
   6. selection
   7. change in frequencies of genes
   8. over time, evolution of new species, etc.

SCIENTIFIC METHOD

• Science: organizes knowledge, makes it accessible to everyone

  PRINCIPLES OF SCIENCE: Judge William R. Overton: 1981

  1. science is guided by natural law
  2. science has to be explanatory by reference to natural law
  3. science is testable against the observable world
  4. science's conclusions are tentative
  5. science is falsifiable

  "scientific-creationism" fails all five criteria

Definitions:

1. Scientific Method - Approach for gathering information  (Fig. 1.11)
   • an example
     1. recognize and state problem. e.g. sugar for diabetics, is it always bad?
     2. collect information and data
     3. formulate a testable hypothesis. e.g., moderate amounts in well balanced meals are safe
     4. make a prediction: no significant difference in blood sugar levels
     5. make observations or perform experiment
     6. formulate a conclusion
   • The Nature of Science from PBS
   • The Scientific Method: an example from the University of Arizona, Biology Project
   • Scientific Method : Environmental Inquiry, Cornell University and Penn State University
   • Observational, Comparative, and Experimental methods of testing hypotheses---Bruce G. Stewart; Murray State College, Oklahoma
     
1. Data - Factual (objective) information collected about the natural world
2. Hypothesis - tentative explanation, consistent with known facts, testable, simpler than competing hypotheses
3. Theories - scientifically accepted general principles, well supported by many tests, powerful 
   • FIVE major unifying biological theories:
     1. cell
     2. biogenesis
     3. homeostasis
     4. evolution
     5. gene
4. Principle or Law: predictions are unvaryingly uniform
5. prediction: a statement of what one should observe in nature if one looks (the if-then process)
6. testing: conducting a scientific experiment
7. Controlled Experiment
8. controls

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Elements of Experiment:

1. Hold all conditions constant except the one being tested (independent or experimental variable, e.g., length of day in a 24 hour period)
2. Deliberately vary the condition to test  (all other variables are held constant)
3. Observe the result of any change that occurs in the dependent variable due to varying the experimental variable.   (the dependent variable is the parameter measured to determine the result or change that   results from varying the experimental variable)
4. Use a control group to compare against tested group
   1. placebo: control in drug experiments to rule out other effects
   2. double-blind: to eliminate any influence of the people doing the experiment.
5. Differences in results between the control and the experimental group are the result of the independent variable being tested.

KEY TERMS FOR CHAPTER 1

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