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A View of LifeA View of Life 1
Defining Life (1)Defining Life (1)
How do you know if something is alive?How do you know if something is alive?
What are properties of living things that non-What are properties of living things that non-livings things do no possess?livings things do no possess?
What is the smallest living thing you can think What is the smallest living thing you can think of?of?
A View of LifeA View of Life
So what is required of life?So what is required of life?
Living “things” are:Living “things” are:
2
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
5Levels of Biological Organization
A View of LifeA View of Life 6Living 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
7Acquiring Nutrients
A View of LifeA View of Life 8Living 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 9Living 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
10Rockhopper Penguins & Offspring
A View of LifeA View of Life 11Living 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
So what is required of life?So what is required of life?
Living “things”Living “things”eateatgive off wastesgive off wastesreproducereproducebreathebreathediedierespond to their environmentrespond to their environmentadaptadaptcontain heritable materialcontain heritable material
12
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
16ClassificationClassification
What kinds of music do you listen What kinds of music do you listen to?to?
What kinds of music are there?What kinds of music are there?
A View of LifeA View of Life 17
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 18
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 19
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
20Domains:The Archaea
21Domains:The Bacteria
A View of LifeA View of Life 22
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
23Domains:The Eukaryote Kindoms
A View of LifeA View of Life 24
Scientific NamesScientific Names
Binomial nomenclatureBinomial nomenclature (two-word names) (two-word names)
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