Great Ideas in Science Great Ideas in Science Lecture 10 - Living ThingsLecture 10 - Living Things

Prof. Robert HazenProf. Robert HazenUNIV-301UNIV-301

Every Living thing…Every Living thing…1.1. Can be Can be classifiedclassified in one scheme in one scheme2.2. Is Is modularmodular – composed of a few – composed of a few

simple moleculessimple molecules3.3. Is made of Is made of cellscells – life – life’’s chemical s chemical

factoriesfactories4.4. Uses the same Uses the same genetic codegenetic code5.5. EvolvedEvolved from a first cell by from a first cell by natural natural

selectionselection6.6. Lives in Lives in ecosystemsecosystems of many of many

interdependent organismsinterdependent organisms

Ways of Thinking Ways of Thinking About Living ThingsAbout Living Things

Biosphere Biosphere Ecosystem Ecosystem CommunityCommunity PopulationPopulation OrganismOrganism Anatomy & Anatomy &

physiologyphysiology CellularCellular MolecularMolecular

What is Life?What is Life?

EncapsulationEncapsulation: All life is separated : All life is separated from the environment by a from the environment by a membranemembrane..

MetabolismMetabolism: All life obtains : All life obtains energyenergy and and atomsatoms from the environment. from the environment.

ReproductionReproduction: All life reproduces : All life reproduces via via geneticsgenetics..

The Characteristics of The Characteristics of LifeLife High degree of order and complexityHigh degree of order and complexity

Part of larger systems of matter and energyPart of larger systems of matter and energy

Life depends on chemical reactions in cellsLife depends on chemical reactions in cells

Life requires liquid waterLife requires liquid water

Organisms grow and developOrganisms grow and develop

Regulate energy useRegulate energy use

Share same genetic code, code is heritableShare same genetic code, code is heritable

All living things are descended from a All living things are descended from a common ancestorcommon ancestor

Linnaean classificationLinnaean classification

HierarchyHierarchy KingdomKingdom PhylumPhylum ClassClass OrderOrder FamilyFamily GenusGenus Species Species

Great Idea: Living things use many different strategies to deal with the

problems of acquiring and using matter and energy.

Why is Taxonomy Why is Taxonomy Important?Important?

Think about how to describe a tree.Think about how to describe a tree.

Names are essential for accurate Names are essential for accurate communicationscommunications

But taxonomy can be ratherBut taxonomy can be rather arbitraryarbitrary

Lumpers versus splittersLumpers versus splitters

Local variations in speciesLocal variations in species

Why is Taxonomy Why is Taxonomy Important?Important?

Dracorex (top left) and Stygimoloch (top right), as growth stages of Pachycephalosaurus (bottom).

Why is Taxonomy Why is Taxonomy Important?Important?

A B C

Classifying LifeClassifying Life KingdomsKingdoms

MoneraMonera ProtistaProtista FungiFungi PlantsPlants Animals Animals

Taxonomy of AnimalsTaxonomy of Animals

Classifying Human BeingsClassifying Human Beings

Kingdom: AnimalsKingdom: Animals Phylum: ChordatesPhylum: Chordates

Subphylum: vertebratesSubphylum: vertebrates Class: MammalsClass: Mammals Order: PrimatesOrder: Primates Family: Family: HominidHominid Genus: Genus: HomoHomo Species: Species: sapienssapiens

A New View:A New View:Three Domains of LifeThree Domains of Life

BacteriaBacteria

ArchaeaArchaea

EukaryaEukarya

Implications of Implications of Linnaean Classification Linnaean Classification

You can use genetic material.You can use genetic material. Similarities depend on time and change.Similarities depend on time and change. Classification results from real events.Classification results from real events.

“Nothing in biology makes sense except in the light of evolution.”

Strategies of FungiStrategies of Fungi

GrowthGrowth FilamentsFilaments Decomposers Decomposers

StructureStructure Mass of filamentsMass of filaments Many formsMany forms

ReproductionReproduction Break filamentsBreak filaments Spores (usually asexual)Spores (usually asexual)

LichensLichens Fungi + AlgaeFungi + Algae Two interdependent speciesTwo interdependent species

The Simplest PlantsThe Simplest Plants Phylum: BryophytesPhylum: Bryophytes StructureStructure

No rootsNo roots Photosynthetic Photosynthetic

ReproductionReproduction Sexual Sexual AsexualAsexual

Vascular PlantsVascular Plants Phylum: vascular plantsPhylum: vascular plants StructureStructure

Roots, stems, leavesRoots, stems, leaves Control water lossControl water loss

ReproductionReproduction Spore = fertilized eggSpore = fertilized egg Cone = holds egg or spermCone = holds egg or sperm Seed = egg plus nutrientsSeed = egg plus nutrients Pollen = spermPollen = sperm

StrategiesStrategies Seedless (Ferns - spores)Seedless (Ferns - spores) Seeds but no flowers Seeds but no flowers

(Gymnosperms - cones)(Gymnosperms - cones) Seeds and flowers Seeds and flowers

(Angiosperms)(Angiosperms)

AngiospermsAngiosperms

InvertebratesInvertebrates No backboneNo backbone Most diverse animalsMost diverse animals

ArthropodsArthropods 70% of known animal 70% of known animal

speciesspecies

StructureStructure ExoskeletonExoskeleton Jointed legsJointed legs

The Molecules of LifeThe Molecules of Life

All life is All life is modularmodular – composed – composed of a few simple molecules.of a few simple molecules.

Key Ideas about the Key Ideas about the molecules of lifemolecules of life

Based on Carbon (Organic chemistry)Based on Carbon (Organic chemistry)

Six main elements (CHNOPS)Six main elements (CHNOPS)

Modular; built from simple unitsModular; built from simple units

Molecular shapes determine their Molecular shapes determine their functionfunction

Nutrition FactsNutrition Facts

LipidsLipids SugarsSugars Amino acidsAmino acids

EnergyEnergy

Carbohydrates (sugars)Carbohydrates (sugars)

Carbon

Hydrogen

Oxygen

Cellulose and StarchCellulose and Starch

LipidsLipids

Saturated and Saturated and Unsaturated LipidsUnsaturated Lipids

Amino AcidsAmino Acids

Amino groupAmino group Carboxyl groupCarboxyl group Side-group (20 Side-group (20

different things)different things)

Protein – sequence of Protein – sequence of amino acidsamino acids

Primary – chain of Primary – chain of amino acidsamino acids

Secondary – folding of Secondary – folding of chainchain

TertiaryTertiary QuaternaryQuaternary

ProteinsProteins Structural roleStructural role

Proteins – EnzymesProteins – Enzymes

Dietary Amino AcidsDietary Amino Acids