Chapter 1

IntroductionIntroduction

to Lifeto Life

on Earthon Earth

Chapter 1 2ƒ1-2

OH H

CH2OH

Levels ofLevels ofBiological Organization IBiological Organization I

SubatomicSubatomic ElectronElectronNeutronNeutronProtonProton

NitrogenNitrogenCarbonCarbonHydrogenHydrogen OxygenOxygen

DNADNAGlucoseGlucoseWaterWater

NucleusNucleusChloroplastChloroplastMitochondrionMitochondrion

Nerve CellNerve Cell

AtomicAtomic

MolecularMolecular

OrganelleOrganelle

CellularCellular

Chapter 1 3ƒ1-2

Levels ofLevels ofBiological Organization IIBiological Organization II

TissueTissue NervousNervousTissueTissue

BrainBrain

NervousNervousSystemSystem

PronghornPronghornAntelopeAntelope

OrganOrgan

(Organ) System(Organ) System

OrganismOrganism

Chapter 1 4ƒ1-2

Levels ofLevels ofBiological Organization IIIBiological Organization III

PopulationPopulationHerd of PronghornsHerd of Pronghorns

HawkHawk

WaterWater

Earth’sEarth’ssurfacesurface

CommunityCommunity

EcosystemEcosystem

BiosphereBiosphere

PronghornsPronghorns

HawkHawk GrassGrass

PronghornsPronghornsSnakeSnakeBushesBushes

SoilSoilAirAir

SnakeSnake

Chapter 1 5§3

PrinciplesPrinciplesUnderlying All ScienceUnderlying All Science

All events can be attributed to natural All events can be attributed to natural causescauses

• Explanations don’t invoke deity (sorry creationists)Explanations don’t invoke deity (sorry creationists)

• But should not specifically exclude deity (since we But should not specifically exclude deity (since we can’t prove it either way)can’t prove it either way)

Natural laws apply at all places and all timesNatural laws apply at all places and all times

People perceive events in similar waysPeople perceive events in similar ways

Chapter 1 6

Chapter 1 7

Chapter 1 8

Chapter 1 9

Chapter 1 10p10

The Scientific MethodThe Scientific Method

Make Make observationobservation (something unexpected (something unexpected happens)happens)

Propose Propose hypothesishypothesis• Potential explanation for observationPotential explanation for observation• Must lead to “if/then” predictionsMust lead to “if/then” predictions

Design & execute Design & execute experimentexperiment• Controlled test of predictionsControlled test of predictions• Designed to challenge hypothesisDesigned to challenge hypothesis

Draw Draw conclusionconclusion (supported or not) (supported or not)

Chapter 1 11p11

Scientific TheoriesScientific TheoriesA general statement about how things A general statement about how things operateoperate

Derived through Derived through inductive reasoninginductive reasoningHas survived thorough challengesHas survived thorough challengesNever permanent or final “truth”Never permanent or final “truth”

• Always provisional (tentative)Always provisional (tentative)• Always subject to change or replacementAlways subject to change or replacement

Used to propose hypotheses (Used to propose hypotheses (deductive deductive reasoningreasoning))

Chapter 1 12§4

Evolution:Evolution:Unifying Theories of BiologyUnifying Theories of Biology

All species evolved from previous speciesAll species evolved from previous species

Theories of origin that emerged from Theories of origin that emerged from inductive reasoninginductive reasoning

• Evolutionary theory emerges from data (true Evolutionary theory emerges from data (true science)science)

• Creationism imposes itself on data (not Creationism imposes itself on data (not science but doctrine of faith)science but doctrine of faith)

Extremely vital web linking all biological Extremely vital web linking all biological informationinformation

Chapter 1 13ƒ1-11

When environment changes:When environment changes:

• Species must adapt to new conditionsSpecies must adapt to new conditions

• Some can’t and go extinctSome can’t and go extinct

• DinosaursDinosaurs

– Experienced changes 65 myaExperienced changes 65 mya

– Were unable to adapt fast enoughWere unable to adapt fast enough

– Globally extinctGlobally extinct

Changing ConditionsChanging Conditions

Chapter 1 14

CharacteristicsCharacteristicsof Living Thingsof Living Things

1.1. Complex, organized & made of cellsComplex, organized & made of cells

2.2. Must get materials & energyMust get materials & energy

3.3. Homeostasis maintains internal Homeostasis maintains internal conditionsconditions

4.4. GrowthGrowth

5.5. Respond to stimuliRespond to stimuli

6.6. Reproduce themselvesReproduce themselves

7.7. Capacity to evolveCapacity to evolve

Chapter 1 15ƒ1-1

Salt; Organized but simpleSalt; Organized but simple

Oceans; Complex but unorganizedOceans; Complex but unorganized

Water flea; Organized and complexWater flea; Organized and complex

Cells are the basic unit of organization in Cells are the basic unit of organization in living thingsliving things

Characteristics:Characteristics:1. Complex, Organized, Cells1. Complex, Organized, Cells

Chapter 1 16p4

Characteristics:Characteristics:2. Respond to Stimuli2. Respond to Stimuli

Changes in internal environmentChanges in internal environment• TemperatureTemperature• Water levelWater level• Blood sugar levelBlood sugar level

Changes in external environmentChanges in external environment• Seek food and waterSeek food and water• Avoid bitternessAvoid bitterness• Plants grow toward lightPlants grow toward light

Chapter 1 17p4

Characteristics:Characteristics:3. Homeostasis3. Homeostasis

Organized systems disintegrateOrganized systems disintegrate

Preventing disintegration requires energyPreventing disintegration requires energy

HomeostasisHomeostasis means “staying the same” means “staying the same”

• Sweating when hot; shivering when coldSweating when hot; shivering when cold

• Thirsting when water is lowThirsting when water is low

Chapter 1 18p5

Characteristics:Characteristics:4. Acquire Materials and Energy4. Acquire Materials and Energy

Homeostasis requires energyHomeostasis requires energy• Opposes natural trend to disintegration Opposes natural trend to disintegration • Obtained from external sourceObtained from external source

Homeostasis requires physical repairHomeostasis requires physical repair• Parts break downParts break down• New materials requiredNew materials required

for repairfor repair

Food supplies material and energyFood supplies material and energy

Chapter 1 19p5

Characteristics:Characteristics:5. Growth5. Growth

Violates homeostasisViolates homeostasis• Homeostasis “staying the same”Homeostasis “staying the same”• Growth = homeostasis plus extraGrowth = homeostasis plus extra

Organism grows in size/massOrganism grows in size/massMust acquire more than needed for Must acquire more than needed for homeostasishomeostasis

Genetically programmedGenetically programmed• TimingTiming• SizeSize• ShapeShape

Chapter 1 20p6

Characteristics:Characteristics:6. Reproduction6. Reproduction

Reproduce themselves in kind (heredity)Reproduce themselves in kind (heredity)

Perpetuation of parents’ geneticsPerpetuation of parents’ genetics• Genetic info stored in DNA chemicalGenetic info stored in DNA chemical• VariationVariation

– Offspring similar to both parentsOffspring similar to both parents– Offspring different from either parentOffspring different from either parent

• Simple code with complex error correction Simple code with complex error correction systemsystem

Chapter 1 21ƒ1-7

Genetic compositionGenetic compositionof population changesof population changes(evolves)(evolves)

• Differential survival (natural selection)Differential survival (natural selection)

• ““Selects” advantageous adaptationsSelects” advantageous adaptations

The more time, the more changeThe more time, the more change

Eventually become much differentEventually become much different

DNADNA

Characteristics:Characteristics:7. Evolution7. Evolution

Chapter 1 22ƒ1-7

1.1. Made of Cells (well, at least 1)Made of Cells (well, at least 1)

2.2. ReproduceReproduce

3.3. Obtain/Use EnergyObtain/Use Energy

4.4. Respond to EnvironmentRespond to Environment

5.5. Grow/DevelopGrow/Develop

Mr. D’s Characteristics Mr. D’s Characteristics of Lifeof Life

Chapter 1 23ƒ1-8

CategorizingCategorizingthe Diversity of Life Ithe Diversity of Life I

Domains Domains BacteriaBacteria & & ArchaeaArchaea

•ProkaryoticProkaryotic•Mostly Mostly unicellularunicellular

Domain Domain EukaryaEukarya is is eukaryoticeukaryotic

•And other And other organellesorganelles

• Cells with distinct membrane-Cells with distinct membrane-bound bound nucleusnucleus

Chapter 1 24ƒ1-8

CategorizingCategorizingthe Diversity of Life IIthe Diversity of Life II

• Kingdom ProtistaKingdom Protista unicellularunicellular

• Kingdom FungiKingdom Fungi multicellular, cell multicellular, cell wall, heterotrophwall, heterotroph

• Kingdom PlantaeKingdom Plantae multicellular, cell wall, multicellular, cell wall, autotrophautotroph

• Kingdom AnimaliaKingdom Animalia multicellular, heterotroph, multicellular, heterotroph, no cell wallno cell wall

Chapter 1 25p8

Variations inVariations inEnergy AcquisitionEnergy Acquisition

PlantaePlantae• Capture light energyCapture light energy• Use to make food from carbon dioxideUse to make food from carbon dioxide• PhotosyntheticPhotosynthetic autotrophsautotrophs

Most others:Most others:• Eat other organisms to get foodEat other organisms to get food• Some absorb particlesSome absorb particles• Others ingest bitesOthers ingest bites• HeterotrophsHeterotrophs

Chapter 1

TheTheEndEnd