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Introduction to Biology

Introduction to Biology. Studying Life’s Diversity and Intricate Processes. Biological Inquiry. Bio = of living things Biological Science: observation, identification, experimental investigation and theoretical explanation of natural phenomena What are the Characteristics of Living Things?

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Introduction to Biology

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  1. Introduction to Biology Studying Life’s Diversity and Intricate Processes

  2. Biological Inquiry • Bio = of living things • Biological Science: observation, identification, experimental investigation and theoretical explanation of natural phenomena • What are the Characteristics of Living Things? • What are Fundamental Concepts that Relate to these Characteristics? • How Do Biologists Study Living Things?

  3. What are common characteristics of living things? • Properties of Life • organization involving cells • energy use and metabolism • response to environmental changes • regulation and homeostasis • growth and development • reproduction • biological evolution

  4. Concept: New Properties Emerge at Each Level in the Biological Hierarchy • Principle of Emergent Properties • New characteristics arise out of the arrangement and interactions of the components of a complex system (whole > sum of the parts) organization

  5. Most Complex LeastComplex Organizational Hierarchy of Life biosphere inhabitable regions of earth ecosystem coral reef (living + nonliving) community coral reef populations population school of fish organism fish organ system nervous system organ brain tissue nervous tissue cell neuron organelle nucleus macromolecule DNA molecule nucleotide atom nitrogen sub-atomic particles protons, neutrons, electrons

  6. Concept: Cells are an Organism’s Basic Units of Structure and Function. • Two types of cells • Prokaryotic • Archaea and Bacteria • few internal membranes • no membrane-bound nucleus • Eukaryotic • Protists, Fungi, Animals, Plants • extensive internal membranes • membrane-bound nucleus organization

  7. Concept: Structure and Function are Correlated at all Levels of Biological Organization. • How is red blood cell structure suited to its function of carrying oxygen? organization

  8. Energy Use and Metabolism • Energy = ability to do work • Energy conversion = change of one form of energy to another • Metabolism = sum of chemical reactions in an organism • Heterotrophic: other feeder • taking in organic molecules produced by other organisms • Autotrophic: self-feeder • photosynthesis = using the energy of the sun to produce organic molecules

  9. Concept: The Continuity of Life is Based on Heritable Information in DNA. • The molecule of heredity = DNA = deoxyribonucleic acid reproductionregulation

  10. Per 23 chromosomes Now estimated at 30,000 genes Proteome: all proteins produced in a cell or organism Genome: complete genetic composition of an organism Genomes and Proteomes reveal evolutionary relationships

  11. Concept: The Continuity of Life is Based on Heritable Information in DNA. Nuclear divisionretaining the original chromosome number Nuclear divisionreducing the chromosome number,leading to sperm or eggs

  12. Concept: The Continuity of Life is Based on Heritable Information in DNA. • Growth = increase in size • Development = change in characteristics growth and development

  13. Concept: Feedback mechanisms regulate biological systems.

  14. Concept: Feedback mechanisms regulate biological systems. • Living things maintain homeostasis= a relatively stable internal condition regulation and homeostasisresponse to environmental changes

  15. Alfalfa leaves oriented toward sunlight to maximize photosynthesis Desert plant leaves oriented verticallyto minimize water loss http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html Plant Responses to Sunlight response to environmental changes

  16. Concept: Evolution Accounts for the Unity and Diversity of Life • Two mechanisms of evolutionary change • Vertical Descent with Mutation: through changes in DNA, new species arise from pre-existing species • Natural Selection: individuals with traits that provide an advantage in the current environment are more likely to survive and reproduce response to environmental changes biological evolution

  17. Concept: Evolution Accounts for the Unity and Diversity of Life • Vertical Descent with Mutation

  18. Concept: Evolution Accounts for the Unity and Diversity of Life • Natural Selection leads to a change in the genetic characteristics of a population  evolution • Adaptation = characteristic that promotes survival and reproduction

  19. The Unity and Diversity of Living Things An Evolutionary Tree of Life The Three Domains of Life Represent the Earliest Branches in Evolutionary History Contains multiple kingdoms

  20. How Do Biologists Study Living Things? • Discovery Science • Collect Data without a pre-stated hypothesis • Make Observations = objective notations of a phenomenon • Can lead to formulation of hypotheses • Example: determine how many amphibian species are present in a specific environment

  21. How Do Biologists Study Living Things? • Hypothesis-based Science • Ask Questions or make Observations • Formulate an Hypothesis: tentative answer to well-framed question • Make Predictions based on hypothesis • Test Predictions by Conducting Experiments • Analyze experimental data • Determine whether data supports hypothesis

  22. How Do Biologists Study Living Things? Biology 21 Definition • An Hypothesis will have • Two measurable variables • Precise relationship between them (relationship = prediction) The relationship between DNA content and length of the cell cycle is a direct proportion.

  23. How Do Biologists Study Living Things? • A good hypothesis is • Testable • experiments can be designed to test predictions from the hypothesis • experimental results must be repeatable • Falsifiable • allows scientists to eliminate alternative hypotheses

  24. How Do Biologists Study Living Things? • Testing hypotheses • Controlled Experiment • test designed to determine the effect of one factor while keeping all other factors constant • experimental = sample treated to test for effect of the factor being studied • control = sample treated like experimental in all ways EXCEPT for the factor being studied

  25. Use of a Controlled Experiment Increasing dose of almonds on subjects with hyperlipidemia. Full almond = 73 grams/day Control = whole wheat muffins (>5% saturated fat) Half almond = half dose almond + half dose muffins All supplements provided equal amounts of energy in the diet. Jenkins, et al., 2002, Circulation 106:1327

  26. How Do Biologists Study Living Things? • Supported Hypotheses • Theory = broad explanation of a natural phenomenon that has been supported by a large body of evidence • Principle or Law = theory that has been supported over a long period of time • Cell Principle • All living things are composed of cells and cell products; all cells come from pre-existing cells. • Principle of Evolution • Principle of Emergent Properties

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