Download 1 Introductory concepts Principles of Biology BIOL 1543 Greig Roberts, DDS Office: SCEN 417 E-Mail: firstname.lastname@example.org 0 Levels of organization Life?s structural hierarchy defines the scope of biology, the scientific study of life 0 Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican Organ system Nervous system Organ Brain Tissue Nervous tissue Cell Nerve cell Organelle Nucleus Molecule DNA Atom Nucleus Brain Spinal cord Nerve Levels of organization An ecosystem consists of all the organisms living in a particular area and the nonliving environmental components All the living organisms in an ecosystem make up a community. A population consists of a localized group of individuals of one species. An individual living entity is an organism. 0 Levels of organization The hierarchy continues downward with Organ systems Organs Tissues Cells Organelles Molecules 0 Living things and their environments Energy flows one-way through an ecosystem from the sun to producers to consumers and exits as heat. 0 Sun Air CO2 O2 CO2 H2O Chemical energy Inflow of light energy Loss of heat energy Producers Cycling of chemical nutrients Consumers Decomposers Soil Ecosystem Cells are the fundamental units of life Eukaryotic cells contain membrane-enclosed organelles, including a DNA-containing nucleus. Prokaryotic cells lack such organelles. 0 Nucleus (contains DNA) Eukar yotic cell Prokar yotic cell DNA (no nucleus) Organelles 25,000 ? All forms of life have common features DNA is the genetic information for constructing the molecules that make up cells and organisms. Each species? genetic instructions are coded in the sequences of the four building blocks making up DNA?s two helically coiled chains. 0 A C T A T A C C G T A G T A All forms of life have common features All organisms share a common set of features Ordered structures Regulation of internal conditions 0 All forms of life have common features Growth and development Energy use Response to environmental stimuli The ability to reproduce and evolve 0 Evolution explains the unity and diversity of life Charles Dar win synthesized the theory of evolution by natural selection. 0 Natural selection is an editing mechanism that occurs when populations or organisms, having inherited variations, are exposed to environmental factors that favor the reproductive success of some individuals over others. Evolution explains the unity and diversity of life 1. Populations with varied inherited traits 2. Elimination of individuals with certain traits 3. Reproduction of survivors 0 All organisms have adaptations that have evolved by means of natural selection. axolotl Killer whale pangolin Hypothesis-based science poses and tests hypotheses Hypothesis-based science involves observations, questions, and hypotheses as tentative answers to questions. Falsifiable predictions are made and tested. Theories are broad explanations with large bodies of evidence. 0 Observations Question Hypothesis # 1: Dead batteries Hypothesis # 2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test prediction Test falsifies hypothesis Test doesn?t falsify hypothesis Biology is all around us everyday Biology is connected to many important issues in our lives Environmental problems and solutions Genetic engineering Medicine Social issues 0
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