Biology Reading Chapter 1Evolution, the themes of Biology and Scientific inquiryInquiring about LifeEvolution: The process of change that has transformed life on Earth from its earliest beings to the diversity of organisms living todayBiology: The scientific study of lifeEvolution is Biology’s core theme and accounts for life’s unity and diversityScientific Inquiry: How scientists ask and attempt to answer questions about the natural worldThe study of life reveals common themes- Organization- Information- Energy and matter- Interactions- EvolutionLevels of biological organization:1. The biosphere: consists of all life on Earth and all the places where life exists: most regions of land, most bodies of water, the atmosphere, and sediments below the ocean floor2. Ecosystems: all living things in a particular areaExamples include deciduous forests, grasslands, deserts, and coral reefs3. Communities: the array of organisms inhabiting a particular ecosystem4. Populations: consists of all the individuals of a species living within the bounds of a specified area5. Organisms: Individual living things6. Organs and organ systems: a body part that carries out a particular function of the body Organ system: teams of organs that cooperate in a larger function7. Tissues: a group of cells that work together performing a specialized function8. Cells: life’s fundamental unit of structure and functionSingle-celled organism: when one cell performs all the functions of lifeMulticellular organism: has a division of labor among specialized cells9. Organelles: various functional components present in cells10. Molecules: a chemical structure consisting of two or more units called atomsTheme: new properties emerge at successive levels of biological organizationReductionism: reduces complex systems to simpler components that are more manageable to study Emergent properties: New properties that arise with each step upward in hierarchy life, owing to the arrangement and interactions of parts as complexity increasesSystems biology: the exploration of a biological system by analyzing the interactions among its partsStructure and functionAnalyzing biological structure gives an idea on what it does and how it worksThe cell: an organism’s basic unit of structure and functionThe cell is the smallest unit of organization that can perform all activities required for lifeThe two main forms of cells: Prokaryotic and eukaryoticProkaryotic cells: cells of the two groups of single-celled microorganisms: bacteria and archaeaEukaryotic cell: contains membrane-enclosed organellesTheme: Life’s processes involve the expression and transmission of genetic informationDNA (deoxyribonucleic acid): genetic material that is contained in chromosomesDNA, the genetic materialWhen a cell divides, the DNA is replicated and each of the cellular offspring inherits a complete set of chromosomes identical to the parent cellGenes: a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNAGene Expression: process by which the information in a gene directs the manufacture of a cellular productGenomics: Large-scale analysis of DNA sequences organisms or virusesGenomics: when researchers study whole sets of genes in one or more speciesProteomics: the study of sets of proteins and their propertiesProteome: the entire set of proteins expressed by a given cell or groupBioinformatics: The use of computational tools to sore, organize, and analyze the huge volume of data that results from high-throughput methodsTheme: Life requires the transfer and transformation of energy and matterProducers: Plants and other photosynthetic organismsConsumers: Organisms that feed n producers and other consumersTheme: From ecosystems to molecules, interactions are important in biological systemsEcosystems: an organism’s interactions with other organisms and the physical environmentEach organism interacts with other organismsFeedback regulation: the output, or product of a process regulates that very processNegative feedback: A loop in which the response reduces the initial stimulusPositive feedback: an end product speeds up its own productionEvolution: the core theme in biologyThe core theme: evolution accounts for the unity and diversity of lifeClassify the diversity of lifeDiversity of life includes at least 100,000 species of fungi, 290,000 plant species, 57,000 vertebrate species, and 1 million insect speciesGrouping species: the basic ideaThree domains of lifeBacteria, archaea, eukaryaThe three kingdoms are distinguished partly by their modes of nutritionUnity in the diversity of lifeSimilarities between organisms are evident at all levels of biological hierarchyCharles Darwin and the Theory of natural selectionDarwin proposed that natural selection is an evolutionary mechanism for descent with modificationNatural selection: the natural environment “selects” for the propagation of certain traitsThe tree of lifeIn studying nature, scientists make observations and test hypothesisScience: a way of knowing- an approach to understanding natural phenomenaMaking observationsData: recorded observationsInductive reasoning: derivation of generalizations from a large number of specific observationsForming and testing hypothesesHypothesis: tentative answer to a well-framed question - An explanation on trialDeductive reasoningDeductive reasoning: logic that flows in the opposite direction, from general to specificQuestions that can and cannot be addressed by scienceA scientific hypothesis must be testableThe flexibility of the scientific processA case study in scientific inquiry: investigating coat coloration in mouse populationsColoration in mice evolved as adaptations that camouflage the mice in their environmentsExperimental variables and controlsExperiment: involves manipulation of one faction in a system in order to see the effects of changing itVariables: factors that very in an experimentControlled experiment: designed to compare an experimental group with a control groupIndependent variable: variable whose value is manipulated or changed during an experimentDependent variable: a variable whose value is measured during an experiment to see if it is influenced by another variableTheories in scienceScientific theory: must broader in scope than a hypothesisScience benefits from a cooperative approach and diverse viewpointsGood communication helps in scienceBuilding on the work of othersModel organism: species that is