PlantsPlants

Common CharacteristicsCommon Characteristics

CharacteristicsCharacteristics

MulticellularMulticellular More than one cellMore than one cell

Cell WallCell Wall Made of celluloseMade of cellulose

EukaryoteEukaryote The cells of these The cells of these

organisms have a nucleusorganisms have a nucleus

Plant HistoryPlant History

First plants are thought to have begun First plants are thought to have begun appearing around 500 million years ago appearing around 500 million years ago (probably looked like (probably looked like moss))

First plant fossils are those called psilophytes First plant fossils are those called psilophytes (some still exist today)(some still exist today)

Scientists used DNA evidence and the Scientists used DNA evidence and the presence of chlorophyll to compare ancient presence of chlorophyll to compare ancient plants with modern plantsplants with modern plants

NOT this MossNOT this Moss

Ancient ExamplesAncient Examples

Adaptations to Living on LandAdaptations to Living on Land

RootsRoots Absorbs water and Absorbs water and

minerals from the soilminerals from the soil Stores food (Ex: carrot)Stores food (Ex: carrot) Anchors a plant to the Anchors a plant to the

groundground Reproduction (Ex: Reproduction (Ex:

Aspen trees)Aspen trees)

Roots con’t.Roots con’t.

Tap RootsTap Roots – one long, – one long, thick main root with thick main root with many smaller roots many smaller roots branching off main rootbranching off main root

Fibrous RootsFibrous Roots – many – many similarly sized roots that similarly sized roots that form a dense tangled form a dense tangled massmass

Quaking Aspen – the largest Quaking Aspen – the largest organism on the planetorganism on the planet

Adaptations con’t.Adaptations con’t.

StemStem Provides structure and Provides structure and

support for upright support for upright growthgrowth

Contains vascular tissue Contains vascular tissue to transport materialsto transport materials

Woody or HerbaceousWoody or Herbaceous CambiumCambium – A layer of – A layer of

cells in a plant that cells in a plant that produces new phloem produces new phloem and xylem cellsand xylem cells

Adaptations con’t.Adaptations con’t.

LeavesLeaves – organ that absorbs sunlight and is – organ that absorbs sunlight and is responsible for photosynthesisresponsible for photosynthesis CuticleCuticle – waxy outer layer that prevents water loss – waxy outer layer that prevents water loss

(also on stems and fruits)(also on stems and fruits) StomataStomata – opening in the leaf that allows for – opening in the leaf that allows for

carbon dioxide to enter and oxygen to exitcarbon dioxide to enter and oxygen to exit Guard cellsGuard cells – surround the stomata to keep it open – surround the stomata to keep it open

during the day and closed at nightduring the day and closed at night

Stomata/Guard CellsStomata/Guard Cells

Photosynthesis RevisitedPhotosynthesis Revisited

The process in which the sun’s energy is The process in which the sun’s energy is converted by a plant, in the chloroplast, to converted by a plant, in the chloroplast, to make foodmake food

Formula:Formula:

Photosynthesis RevisitedPhotosynthesis Revisited

Leaves con’t.Leaves con’t.

Types of PlantsTypes of Plants

NonvascularNonvascular – do not – do not have vascular tissue, have vascular tissue, usually no more than a usually no more than a few cells thick, live few cells thick, live close to waterclose to water

VascularVascular – contain – contain vascular tissue, vascular tissue, specially adapted to specially adapted to transport materials, transport materials, enables taller growthenables taller growth

Nonvascular PlantsNonvascular Plants

Primary methods of transporting materials are: Primary methods of transporting materials are: OsmosisOsmosis – diffusion of water through a selectively – diffusion of water through a selectively

permeable membranepermeable membrane DiffusionDiffusion – movement of particles from an area of – movement of particles from an area of

high concentration to an area of low concentrationhigh concentration to an area of low concentration

Nonvascular PlantsNonvascular PlantsExamplesExamples

Vascular PlantsVascular Plants

Contain Vascular TissuesContain Vascular Tissues XylemXylem – transports water and nutrients up the – transports water and nutrients up the

plantplant

PhloemPhloem – transports food down the plant – transports food down the plant

Vascular PlantsVascular PlantsExamplesExamples

Other adaptationsOther adaptations

PhototropismPhototropism – when – when plant growth is plant growth is determined by light determined by light (arctic poppy)(arctic poppy)

ThigmotropismThigmotropism – when – when plant growth is plant growth is determined by touch determined by touch (ivy, pole beans)(ivy, pole beans)

Other adaptationsOther adaptations

GravitropismGravitropism – when – when plant growth is plant growth is determined by gravity determined by gravity (most plants)(most plants)

Carnivorous plantsCarnivorous plants Uniquely adapted to Uniquely adapted to

survive in areas with survive in areas with poor soil (Bladderwort, poor soil (Bladderwort, Venus Fly Trap)Venus Fly Trap)

Uses/Benefits of PlantsUses/Benefits of Plants

Aesthetics – look and smell nice, increase the value Aesthetics – look and smell nice, increase the value of a homeof a home

Lumber – building, firewoodLumber – building, firewood Shade – energy efficientShade – energy efficient PaperPaper Food – fruits and vegetablesFood – fruits and vegetables HealthHealth

Medicines (Medicines (http://www.rain-tree.com/plantdrugs.htm)) Air Quality (Ginkgo biloba)Air Quality (Ginkgo biloba)