chapter_01_powerpoint_le A View of Life

8/7/2019 chapter_01_powerpoint_le A View of Life

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A View of Life

Chapter 01


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A View of LifeA View of Life 2

OutlineOutline

Defining LifeDefining Life -- Emergent PropertiesEmergent Properties

Materials and EnergyMaterials and Energy

Reproduction and DevelopmentReproduction and Development

Adaptations and Natural SelectionAdaptations and Natural Selection

Biosphere OrganizationBiosphere Organization

Human PopulationHuman PopulationBiodiversityBiodiversity

ClassificationClassification

The Scientific MethodThe Scientific Method


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Defining Life (1)Defining Life (1)

Living things vs. nonliving objects:Living things vs. nonliving objects:

Comprised of the same chemical elementsComprised of the same chemical elements

Obey the same physical and chemical lawsObey the same physical and chemical laws

The cell is the smallest, most basic unit of allThe cell is the smallest, most basic unit of alllifelife

Familiar organisms are multicellularFamiliar organisms are multicellular

Some cells independentSome cells independent singlesingle--celledcelledorganismsorganisms


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4Defining Life


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6Levels of Biological Organization


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A View of LifeA View of Life 7Living Things:Living Things:

Acquire & Process FoodAcquire & Process Food

EnergyEnergy -- the capacity to do workthe capacity to do work

The sun:The sun:

--Ultimate source of energy for nearly all life onUltimate source of energy for nearly all life onEarthEarth

--Drives photosynthesisDrives photosynthesis

MetabolismMetabolism -- all the chemical reactions in aall the chemical reactions in acellcell

--HomeostasisHomeostasis -- Maintenance of internalMaintenance of internal

conditions within certain boundariesconditions within certain boundaries


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Respond to StimuliRespond to Stimuli

Living things detect changes in environmentLiving things detect changes in environment

ResponseResponse often involves movementoften involves movement

Vulture can detect and find carrion a mileVulture can detect and find carrion a mileawayaway

Monarch butterfly senses fall and migratesMonarch butterfly senses fall and migratessouthsouth

Microroganisms follow light or chemicalsMicroroganisms follow light or chemicals

Even leaves of plants follow sunEven leaves of plants follow sun

Responses collectively constituteResponses collectively constitute behaviorbehavior


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Reproduce and DevelopReproduce and Develop

Organisms live and dieOrganisms live and die

Must reproduce to maintain populationMust reproduce to maintain population

Multicellular organisms:Multicellular organisms:

Begins with union of sperm and eggBegins with union of sperm and egg

Developmental instructions encoded in genesDevelopmental instructions encoded in genes

--Composed of DNAComposed of DNA

--Long spiral molecule inLong spiral molecule in chromosomeschromosomes


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11Rockhopper Penguins & Offspring


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Adapt to ChangeAdapt to Change

AdaptationAdaptation

Any modification that makes an organismAny modification that makes an organismmore suited to its way of lifemore suited to its way of life

Organisms, become modified over timeOrganisms, become modified over time

However, organisms very similar at basic levelHowever, organisms very similar at basic level

--Suggests living things descended from sameSuggests living things descended from sameancestorancestor

--Descent with modificationDescent with modification -- EvolutionEvolution

--Caused byCaused by natural selectionnatural selection


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Organization of the BiosphereOrganization of the Biosphere

PopulationPopulation -- Members of a species within anMembers of a species within anareaarea

CommunityCommunity -- A local collection of interactingA local collection of interactingpopulationspopulations

EcosystemEcosystem -- The communities in an areaThe communities in an areaconsidered with their physical environmentconsidered with their physical environment

--How chemicals are cycled and reHow chemicals are cycled and re--used byused byorganismsorganisms

--How energy flows, from photosynthetic plantsHow energy flows, from photosynthetic plantsto top predatorsto top predators


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14Terrestrial Ecosystems:A Grassland


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Human PopulationsHuman Populations

Ecosystems negatively impacted by humanEcosystems negatively impacted by humanpopulationspopulations

Destroyed for agriculture, housing, industry, etc.Destroyed for agriculture, housing, industry, etc.

Degraded and destabilized by pollutionDegraded and destabilized by pollution

However, humans depend uponHowever, humans depend upon healthyhealthyecosystemsecosystemsforfor

FoodFoodMedicinesMedicines

Raw materialsRaw materials

Other ecosystem processesOther ecosystem processes


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BiodiversityBiodiversity

Biodiversity:Biodiversity:

The total number of species (est. 15 million)The total number of species (est. 15 million)

The variability of their genes, andThe variability of their genes, and

The ecosystems in which they liveThe ecosystems in which they live

Extinction:Extinction:

The death of the last member of a speciesThe death of the last member of a species

Estimates of 400 species/day lost worldwideEstimates of 400 species/day lost worldwide


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Taxonomy:Taxonomy:

The rules for identifying and classifyingThe rules for identifying and classifyingorganismsorganisms

Hierarchical levels (taxa) based onHierarchical levels (taxa) based onhypothesized evolutionary relationshipshypothesized evolutionary relationships

Levels are, from least inclusive to mostLevels are, from least inclusive to mostinclusive:inclusive:

--Species, genus, family, order, class, phylum,Species, genus, family, order, class, phylum,kingdom, and domainkingdom, and domain

--A level usually includes more species than theA level usually includes more species than thelevel below it, and fewer species than the onelevel below it, and fewer species than the one

above itabove it


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Levels of ClassificationLevels of Classification

Z. maysZ. maysH. sapiensH. sapiensSpeciesSpecies

ZeaZeaHomoHomoGenusGenus

PoacaePoacaeHominidaeHominidaeFamilyFamily

CommelinalesCommelinalesPrimatesPrimatesOrderOrder

LiliopsidaLiliopsidaMammaliaMammaliaClassClass

AnthophytaAnthophytaChordataChordataPhylumPhylum

PlantaePlantaeAnimaliaAnimaliaKingdomKingdom

EukaryaEukaryaEukaryaEukaryaDomainDomain

CornCornHumanHumanTaxonTaxon


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DomainsDomains

BacteriaBacteria

Microscopic unicellular prokaryotesMicroscopic unicellular prokaryotes

ArchaeaArchaea

BacteriaBacteria--like unicellular prokaryoteslike unicellular prokaryotes

Extreme aquatic environmentsExtreme aquatic environments

EukaryaEukarya

EukaryotesEukaryotes Familiar organismsFamiliar organisms


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21Domains:The Archaea


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KingdomsKingdoms

ArchaeaArchaea Kingdoms still being worked outKingdoms still being worked out

BacteriaBacteria -- Kingdoms still being worked outKingdoms still being worked out

EukaryaEukarya

KingdomKingdom ProtistaProtista

KingdomKingdom FungiFungi

KingdomKingdom PlantaePlantae

KingdomKingdom AnimaliaAnimalia


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24Domains:The Eukaryote Kindoms


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Scientific NamesScientific Names

Binomial nomenclatureBinomial nomenclature (two(two--word namess)word namess)

UniversalUniversal

LatinLatin--basedbased

First word representsFirst word represents genusgenus of organismof organism

Second word isSecond word is specific epithetspecific epithet of a speciesof a specieswithin the genuswithin the genus

Always Italicized asaAlways Italicized asa Genus speciesGenus species ((HomoHomosapienssapiens))

Genus may occur alone (Genus may occur alone (HomoHomo), but not), but not

specific epithetspecific epithet


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A View of LifeA View of Life 26The Scientific Method:The Scientific Method:

Observation and HypothesisObservation and Hypothesis

Begins withBegins with observationobservation

Scientists use their five sensesScientists use their five senses

Instruments can extend the range of sensesInstruments can extend the range of senses

HypothesisHypothesis

A tentative explanation for what wasA tentative explanation for what wasobservedobserved

Developed through inductively reasoningDeveloped through inductively reasoning

from specific to generalfrom specific to general


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A View of LifeA View of Life 30The Scientific Method:The Scientific Method:

Conclusion and ReviewConclusion and Review

The results areThe results are analyzedanalyzed andand interpretedinterpreted

ConclusionsConclusions are what the scientist thinksare what the scientist thinks

caused the resultscaused the results

Findings must be reported in scientificFindings must be reported in scientificjournalsjournals

Peers reviewPeers review the findings and the conclusionsthe findings and the conclusions

Other scientists then attempt toOther scientists then attempt to duplicateduplicate orordismissdismiss the published findingsthe published findings


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A View of LifeA View of Life 32Controlled Experiments:Controlled Experiments:

The VariablesThe Variables

Experimental (Experimental (IndependentIndependent) variable) variable

Applied one way to experimental groupApplied one way to experimental group

Applied a different way to control groupApplied a different way to control group

Response (Response (dependentdependent) variable) variable

Variable that is measured to generate dataVariable that is measured to generate data

Expected to yield different results in controlExpected to yield different results in controlversus experimental groupsversus experimental groups


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Observation & HypothesesObservation & Hypotheses

Observations:Observations:

Nitrate fertilizers boost grain crops, but mayNitrate fertilizers boost grain crops, but maydamage soilsdamage soils

When grain crops are rotated with pigeon peaWhen grain crops are rotated with pigeon peait adds natural nitrogenit adds natural nitrogen

Hypothesis:Hypothesis:

Pigeon pea rotation will boost cropPigeon pea rotation will boost cropproduction as much as nitratesproduction as much as nitrates

Pigeon pea rotation will NOT damage soilsPigeon pea rotation will NOT damage soils


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34Root Nodules


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C R t ti St d


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36Crop Rotation Study


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ResultsResults

Experimental Prediction:Experimental Prediction:

Wheat production following pigeon peaWheat production following pigeon pearotation will be equal or better than followingrotation will be equal or better than followingnitrate fertilizernitrate fertilizer

ResultsResults

45 kg/ha produced slightly better than45 kg/ha produced slightly better thancontrolscontrols

90 kg/ha produced nearly twice as much as90 kg/ha produced nearly twice as much ascontrolscontrols

Pigeon pea rotation did not produce as muchPigeon pea rotation did not produce as much

as the controlsas the controls


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Conclusion & RevisionConclusion & Revision

ConclusionConclusion

Research hypothesis was not supported byResearch hypothesis was not supported byresultsresults

However, research hypothesis was not provenHowever, research hypothesis was not provenfalse by negative resultsfalse by negative results

Revised experimentRevised experiment

Grow wheat in same pots for severalGrow wheat in same pots for severalgenerationsgenerations

Look for soil damage in nitrate pots andLook for soil damage in nitrate pots and

improved production in pigeon pea potsimproved production in pigeon pea pots


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Revised Results & ConclusionRevised Results & Conclusion

ResultsResultsAfter second year:After second year:

--Production following nitrates declinedProduction following nitrates declined

--Production following pigeon pea rotation wasProduction following pigeon pea rotation wasgreatest of allgreatest of all

After third yearAfter third year

--Pigeon pea rotation produced 4X as much asPigeon pea rotation produced 4X as much ascontrolscontrols

Revised conclusionsRevised conclusions

Research hypothesis supportedResearch hypothesis supported

Pigeon pea rotation should be recommendedPigeon pea rotation should be recommended

over nitratesover nitrates


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ReviewReview

Defining LifeDefining Life -- Emergent PropertiesEmergent Properties

Materials and EnergyMaterials and Energy

Reproduction and DevelopmentReproduction and Development

Adaptations and Natural SelectionAdaptations and Natural Selection

Biosphere OrganizationBiosphere Organization

Human PopulationHuman Population

BiodiversityBiodiversity


The Scientific MethodThe Scientific Method


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A View of Life

Ending Slide Chapter 01

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