BIO$10$ $ Chapter$1$Introduction$to$Biology$$1$Chapter 1: Introduction to Chapter 1: Introduction to The Diversity of LifeThe Diversity of Life •• Properties of LifeProperties of Life •• Organization of LifeOrganization of Life •• Biological Themes and Unifying TheoriesBiological Themes and Unifying Theories •• Scientific MethodScientific Method Biology: study of living thingsBiology: study of living things Living things can be divided into 6 kingdomsLiving things can be divided into 6 kingdoms Properties of LifeProperties of Life But what dBut what does it mean to be alive?oes it mean to be alive? Living organisms and Living organisms and many nonmany non--living things share three propertiesliving things share three properties •• ComplexityComplexity •• MovementMovement •• Response to stimulationResponse to stimulation All living organisms share 5 basic propertiesAll living organisms share 5 basic properties 1. Cellular Organization: All are composed of at least one 1. Cellular Organization: All are composed of at least one cellcell 2. Met2. Metabolism: All use energyabolism: All use energy 3. Homeostasis: All maintain stable internal conditions3. Homeostasis: All maintain stable internal conditions 4. Growth and reproduction4. Growth and reproduction 5. Heredity: All have a genetic system that is based on 5. Heredity: All have a genetic system that is based on DNA (Deoxyribonucleic acid)DNA (Deoxyribonucleic acid) The Organization of LifeThe Organization of Life Living organisms function and inteLiving organisms function and interact with each other at ract with each other at many levelsmany levels. . These levels are organized in a hierarchy of These levels are organized in a hierarchy of increasing complexityincreasing complexity •• Cellular LevelCellular Level •• Organismal LevelOrganismal Level •• Populational LevelPopulational Level Each higher level contains novel properties not present at the Each higher level contains novel properties not present at the simpler level of organizationsimpler level of organization •• These These properties are termed emergent propertiesproperties are termed emergent propertiesBIO$10$ $ Chapter$1$Introduction$to$Biology$$2$ The Organization of LifeThe Organization of Life $BIO$10$ $ Chapter$1$Introduction$to$Biology$$3$ 5 general themes unify and explain biology as a science 5 general themes unify and explain biology as a science 1.1. EvolutionEvolution 2.2. Energy flowEnergy flow 3.3. Structure determines functionStructure determines function 4.4. CooperationCooperation 5.5. homeostasishomeostasis 1. Evolution1. Evolution: : The genetic change in a speciThe genetic change in a species over timees over time It is a result of a process termed natural selectionIt is a result of a process termed natural selection Variation may also be caused by artificial selectionVariation may also be caused by artificial selection 2. The Flow of Energy2. The Flow of Energy: : All living organisms require energyAll living organisms require energy The sun is the source of energy for ecosystemsThe sun is the source of energy for ecosystems.. Plants capture energy via Plants capture energy via photosynthesisphotosynthesis.. They then act as an energy source for other organismsThey then act as an energy source for other organisms 3. Cooperation3. Cooperation: : Cooperation between organisms is critical for Cooperation between organisms is critical for evolutionevolution. . Symbiosis occurs when two organisms of Symbiosis occurs when two organisms of different species live in direct contactdifferent species live in direct contact.. 4. Structure Determin4. Structure Determines Functiones Function: : Biological structures are Biological structures are well suited to their functionwell suited to their function. . This is true at every level of This is true at every level of organizationorganization.. 5. Homeostasis5. Homeostasis: : All living organisms act All living organisms act to maintain a to maintain a relatively stable relatively stable internal environmentinternal environment.. Maintaining Maintaining homeostasis requires a lot homeostasis requires a lot of signaling backof signaling back--andand--forth forth between cellsbetween cells..BIO$10$ $ Chapter$1$Introduction$to$Biology$$4$ StagStages of Scientific Investigationes of Scientific Investigation •• Facts, Hypotheses and TheoriesFacts, Hypotheses and Theories.. •• Observable, verifiable truths are factsObservable, verifiable truths are facts.. •• Testable explanations for them are hypothesesTestable explanations for them are hypotheses.. •• WWell, supported hypotheses are theoriesell, supported hypotheses are theories.. Theory and CTheory and Certaintyertainty Theory: a set of hypotheses that have been tested many Theory: a set of hypotheses that have been tested many times and not rejectedtimes and not rejected It indicates a higher degree of certaintyIt indicates a higher degree of certainty However, there is no absolute truth in science However, there is no absolute truth in science So the acceptance of a theory is provisionalSo the acceptance of a theory is provisional To scientists, a theory repreTo scientists, a theory represents that of which they are most sents that of which they are most certaincertain.. To the general public, a theory represents lack of knowledge or To the general public, a theory represents lack of knowledge or a guessa guess The scientific “method”The scientific “method”: : A series of logical “either/or” A series of logical “either/or” predictions tested by experiments to reject alternative predictions tested by experiments to reject alternative hypotheseshypothesesBIO$10$ $ Chapter$1$Introduction$to$Biology$$5$ FourFour Theories Unify Biology Theories Unify Biology 1. The Cell Theory1. The Cell Theory 3. The Theory of Heredity3. The Theory of Heredity 2. The Gene Theory2. The Gene Theory 4. The Theory of Evolution4. The Theory of Evolution The Cell The Cell Theory: Theory: Organization Organization of Lifeof Life Robert Hooke, 1665: Discovered cells Robert Hooke, 1665: Discovered cells Anton van Leeuwenhoek, 1670s. Discovered Anton van Leeuwenhoek, 1670s.