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A View of LifeChapter 01
A View of LifeA View of Life 2
OutlineOutline
Defining Life - Emergent PropertiesDefining Life - Emergent 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
ClassificationClassification
The Scientific MethodThe Scientific Method
A View of LifeA View of Life 3
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 all The cell is the smallest, most basic unit of all lifelife
Familiar organisms are multicellularFamiliar organisms are multicellular
Some cells independent – single-celled Some cells independent – single-celled organismsorganisms
4Defining Life
A View of LifeA View of Life 5
Defining Life (2)Defining Life (2)
Emergent Properties – Biological organizationEmergent Properties – Biological organization
Levels range from extreme micro to globalLevels range from extreme micro to global
Each level up:Each level up:
More complex than preceding levelMore complex than preceding level
Properties:Properties:
A superset of preceding level’s propertiesA superset of preceding level’s properties
Emerge from interactions between componentsEmerge from interactions between components
6Levels of Biological Organization
A View of LifeA View of Life 7Living Things:Living Things:Acquire & Process FoodAcquire & Process Food
EnergyEnergy - the capacity to do work - the capacity to do work
The sun:The sun:
Ultimate source of energy for nearly all life on Ultimate source of energy for nearly all life on EarthEarth
Drives photosynthesisDrives photosynthesis
MetabolismMetabolism - all the chemical reactions in a - all the chemical reactions in a cellcell
HomeostasisHomeostasis - Maintenance of internal - Maintenance of internal conditions within certain boundariesconditions within certain boundaries
8Acquiring Nutrients
A View of LifeA View of Life 9Living Things:Living Things:Respond to StimuliRespond to Stimuli
Living things detect changes in environmentLiving things detect changes in environment
ResponseResponse often involves movement often involves movement
Vulture can detect and find carrion a mile Vulture can detect and find carrion a mile awayaway
Monarch butterfly senses fall and migrates Monarch butterfly senses fall and migrates southsouth
Microroganisms follow light or chemicalsMicroroganisms follow light or chemicals
Even leaves of plants follow sunEven leaves of plants follow sun
Responses collectively constitute Responses collectively constitute behaviorbehavior
A View of LifeA View of Life 10Living Things:Living Things: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 in Long spiral molecule in chromosomeschromosomes
11Rockhopper Penguins & Offspring
A View of LifeA View of Life 12Living Things:Living Things:Adapt to ChangeAdapt to Change
AdaptationAdaptation
Any modification that makes an organism Any modification that makes an organism more 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 same Suggests living things descended from same ancestorancestor
Descent with modification - Descent with modification - EvolutionEvolution
Caused by Caused by natural selectionnatural selection
A View of LifeA View of Life 13
Organization of the BiosphereOrganization of the Biosphere
PopulationPopulation - Members of a species within an - Members of a species within an areaarea
CommunityCommunity - A local collection of interacting - A local collection of interacting populationspopulations
EcosystemEcosystem - The communities in an area - The communities in an area considered with their physical environmentconsidered with their physical environment
How chemicals are cycled and re-used by How chemicals are cycled and re-used by organismsorganisms
How energy flows, from photosynthetic plants How energy flows, from photosynthetic plants to top predatorsto top predators
14Terrestrial Ecosystems:A Grassland
15Marine Ecosystems:A Coral Reef
A View of LifeA View of Life 16
Human PopulationsHuman Populations
Ecosystems negatively impacted by human Ecosystems negatively impacted by human populationspopulations
Destroyed for agriculture, housing, industry, etc.Destroyed for agriculture, housing, industry, etc.
Degraded and destabilized by pollutionDegraded and destabilized by pollution
However, humans depend upon However, humans depend upon healthyhealthy ecosystems ecosystems forfor
FoodFood
MedicinesMedicines
Raw materialsRaw materials
Other ecosystem processesOther ecosystem processes
A View of LifeA View of Life 17
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
A View of LifeA View of Life 18
ClassificationClassification
Taxonomy:Taxonomy:The rules for identifying and classifying The rules for identifying and classifying organismsorganisms
Hierarchical levels (taxa) based on Hierarchical levels (taxa) based on hypothesized evolutionary relationshipshypothesized evolutionary relationships
Levels are, from least inclusive to most Levels are, from least inclusive to most inclusive: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 the A level usually includes more species than the level below it, and fewer species than the one level below it, and fewer species than the one above itabove it
A View of LifeA View of Life 19
Levels of ClassificationLevels of Classification
Z. maysZ. maysH. sapiensH. sapiensSpeciesSpecies
ZeaZeaHomoHomoGenusGenus
PoacaePoacaeHominidaeHominidaeFamilyFamily
CommelinalesCommelinalesPrimatesPrimatesOrderOrder
LiliopsidaLiliopsidaMammaliaMammaliaClassClass
AnthophytaAnthophytaChordataChordataPhylumPhylum
PlantaePlantaeAnimaliaAnimaliaKingdomKingdom
EukaryaEukaryaEukaryaEukaryaDomainDomain
CornCornHumanHumanTaxonTaxon
A View of LifeA View of Life 20
DomainsDomains
BacteriaBacteria
Microscopic unicellular prokaryotesMicroscopic unicellular prokaryotes
ArchaeaArchaea
Bacteria-like unicellular prokaryotesBacteria-like unicellular prokaryotes
Extreme aquatic environmentsExtreme aquatic environments
EukaryaEukarya
Eukaryotes – Familiar organismsEukaryotes – Familiar organisms
21Domains:The Archaea
22Domains:The Bacteria
A View of LifeA View of Life 23
KingdomsKingdoms
ArchaeaArchaea – Kingdoms still being worked out – Kingdoms still being worked out
BacteriaBacteria - Kingdoms still being worked out - Kingdoms still being worked out
EukaryaEukarya
Kingdom Kingdom ProtistaProtista
Kingdom Kingdom FungiFungi
Kingdom Kingdom PlantaePlantae
Kingdom Kingdom AnimaliaAnimalia
24Domains:The Eukaryote Kindoms
A View of LifeA View of Life 25
Scientific NamesScientific Names
Binomial nomenclatureBinomial nomenclature (two-word namess) (two-word namess)
UniversalUniversal
Latin-basedLatin-based
First word represents First word represents genusgenus of organism of organism
Second word is Second word is specific epithetspecific epithet of a species of a species within the genuswithin the genus
Always Italicized asa Always Italicized asa Genus speciesGenus species ( (Homo Homo sapienssapiens))
Genus may occur alone (Genus may occur alone (HomoHomo), but not ), but not specific epithetspecific epithet
A View of LifeA View of Life 26The Scientific Method:The Scientific Method:Observation and HypothesisObservation and Hypothesis
Begins with Begins 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 was A tentative explanation for what was observedobserved
Developed through inductively reasoning Developed through inductively reasoning from specific to generalfrom specific to general
27The Scientific Method:
A Flow Diagram
A View of LifeA View of Life 28The Scientific Method:The Scientific Method:ExperimentationExperimentation
ExperimentationExperimentation Purpose is to challenge the hypothesisPurpose is to challenge the hypothesis Designed through deductively reasoning Designed through deductively reasoning
from general to specificfrom general to specific Often divides subjects into a Often divides subjects into a control groupcontrol group
and an and an experimental groupexperimental group PredictsPredicts how groups should differ if how groups should differ if
hypothesis is validhypothesis is valid If prediction happens, hypothesis is If prediction happens, hypothesis is
unchallengedunchallenged
If not, hypothesis is unsupportableIf not, hypothesis is unsupportable
A View of LifeA View of Life 29The Scientific Method:The Scientific Method:ResultsResults
ResultsResults
Observable, objective results from an Observable, objective results from an experimentexperiment
Strength of the data expressed in probabilitiesStrength of the data expressed in probabilities
The probability that random variation could The probability that random variation could have caused the resultshave caused the results
Low probability (less than 5%) is goodLow probability (less than 5%) is good
Higher probabilities make it difficult to dismiss Higher probabilities make it difficult to dismiss random chance as the sole cause of the resultsrandom chance as the sole cause of the results
A View of LifeA View of Life 30The Scientific Method:The Scientific Method:Conclusion and ReviewConclusion and Review
The results are The results are analyzedanalyzed and and interpretedinterpreted
ConclusionsConclusions are what the scientist thinks are what the scientist thinks caused the resultscaused the results
Findings must be reported in scientific Findings must be reported in scientific journalsjournals
Peers reviewPeers review the findings and the conclusions the findings and the conclusions
Other scientists then attempt to Other scientists then attempt to duplicateduplicate or or dismissdismiss the published findings the published findings
A View of LifeA View of Life 31
Scientific TheoryScientific Theory
Scientific TheoryScientific Theory::
Joins together two or more related Joins together two or more related hypotheseshypotheses
Supported by broad range of observations, Supported by broad range of observations, experiments, and dataexperiments, and data
Scientific PrincipleScientific Principle / / LawLaw::
Widely accepted set of theoriesWidely accepted set of theories
No serious challenges to validityNo serious challenges to validity
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 control Expected to yield different results in control versus experimental groupsversus experimental groups
A View of LifeA View of Life 33Controlled Experiments:Controlled Experiments:Observation & HypothesesObservation & Hypotheses
Observations:Observations:
Nitrate fertilizers boost grain crops, but may Nitrate fertilizers boost grain crops, but may damage soilsdamage soils
When grain crops are rotated with pigeon pea When grain crops are rotated with pigeon pea it adds natural nitrogenit adds natural nitrogen
Hypothesis:Hypothesis:
Pigeon pea rotation will boost crop production Pigeon pea rotation will boost crop production as much as nitratesas much as nitrates
Pigeon pea rotation will NOT damage soilsPigeon pea rotation will NOT damage soils
34Root Nodules
A View of LifeA View of Life 35Controlled Experiments:Controlled Experiments:Experimental DesignExperimental Design
Experimental DesignExperimental DesignControl GroupControl GroupWinter wheat planted in pots without fertilizerWinter wheat planted in pots without fertilizer
Experimental GroupsExperimental Groups 1-Winter wheat planted in pots with 45 kg/ha 1-Winter wheat planted in pots with 45 kg/ha nitratenitrate
2-Winter wheat planted in pots with 90 kg/ha 2-Winter wheat planted in pots with 90 kg/ha nitratenitrate
3-Winter wheat planted in pots that had grown a 3-Winter wheat planted in pots that had grown a crop of pigeon peascrop of pigeon peas
All groups treated identically except for aboveAll groups treated identically except for above
36Crop Rotation Study
A View of LifeA View of Life 37Controlled Experiments:Controlled Experiments:ResultsResults
Experimental Prediction:Experimental Prediction:Wheat production following pigeon pea Wheat production following pigeon pea rotation will be equal or better than following rotation will be equal or better than following nitrate fertilizernitrate fertilizer
ResultsResults45 kg/ha produced slightly better than 45 kg/ha produced slightly better than controlscontrols
90 kg/ha produced nearly twice as much as 90 kg/ha produced nearly twice as much as controlscontrols
Pigeon pea rotation did not produce as much Pigeon pea rotation did not produce as much as the controlsas the controls
A View of LifeA View of Life 38Controlled Experiments:Controlled Experiments:Conclusion & RevisionConclusion & Revision
ConclusionConclusion
Research hypothesis was not supported by Research hypothesis was not supported by resultsresults
However, research hypothesis was not proven However, research hypothesis was not proven false by negative resultsfalse by negative results
Revised experimentRevised experiment
Grow wheat in same pots for several Grow wheat in same pots for several generationsgenerations
Look for soil damage in nitrate pots and Look for soil damage in nitrate pots and improved production in pigeon pea potsimproved production in pigeon pea pots
A View of LifeA View of Life 39Controlled Experiments:Controlled Experiments:Revised Results & ConclusionRevised Results & Conclusion
ResultsResultsAfter second year:After second year: Production following nitrates declinedProduction following nitrates declined Production following pigeon pea rotation was Production following pigeon pea rotation was greatest of allgreatest of all
After third yearAfter third year Pigeon pea rotation produced 4X as much as Pigeon pea rotation produced 4X as much as controlscontrols
Revised conclusionsRevised conclusionsResearch hypothesis supportedResearch hypothesis supportedPigeon pea rotation should be recommended Pigeon pea rotation should be recommended over nitratesover nitrates
40A Field Study
A View of LifeA View of Life 41
ReviewReview
Defining Life - Emergent PropertiesDefining Life - Emergent 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
ClassificationClassification
The Scientific MethodThe Scientific Method
A View of LifeEnding Slide Chapter 01