Plants with SeedsPlants with Seeds

StructureStructure – –

LeavesLeaves

stem stem

rootsroots

LeavesLeaves

Function of leavesFunction of leaves

Trap light energy for photosynthesisTrap light energy for photosynthesis Producing sugar from photosynthesisProducing sugar from photosynthesis

Take in waterTake in water

Exchange of gases – Exchange of gases – oxygen and carbon dioxideoxygen and carbon dioxide

Parts of LeavesParts of Leaves

CompoundCompound SimpleSimple StalkStalk: connects leaves : connects leaves to the stemto the stem

BladesBlades: thin flat part that : thin flat part that is the site of is the site of photosynthesisphotosynthesis Simple leaf: 1 single leafSimple leaf: 1 single leaf

Ex. Maple, Oak, AppleEx. Maple, Oak, Apple Compound: divided into a Compound: divided into a

# of separate parts# of separate parts Ex. Roses, clovers, and Ex. Roses, clovers, and

palmspalms

StructureStructureWide

Helps to catch more light energy

Thin

Help get carbon dioxide from bottom to top of leaf for photosynthesis

Internal Parts of LeavesInternal Parts of Leaves

EpidermisEpidermis: outside : outside layer of leaf covered layer of leaf covered in cuticlein cuticle StomataStomata: pores where : pores where

COCO2 2 and H and H22O enter O enter the leaf and Othe leaf and O22 leaves leaves

Guard CellsGuard Cells: cells on : cells on both sides of stomata both sides of stomata that open and closethat open and close

Internal Parts of LeavesInternal Parts of Leaves

MesophyllMesophyll: inner : inner layer of leaflayer of leaf PallisadePallisade: upper : upper

mesophyll where mesophyll where photosynthesis photosynthesis happenshappens

Spongy LayerSpongy Layer: filled : filled with air spaces for with air spaces for COCO2 2 ,H ,H22O and OO and O22

Leaf structureLeaf structure

Greener on top

CO2 gets in here

Most chlorophyll

Leaf diagram – palisade layerLeaf diagram – palisade layer

CO2

Most chlorophyll

Gas exchange Gas exchange

Leaves are designed to allow carbon Leaves are designed to allow carbon dioxide to get to the main chlorophyll dioxide to get to the main chlorophyll layer at the top of the leaflayer at the top of the leaf

They have small holes called stomata on They have small holes called stomata on the under surfacethe under surface

Each hole is open & closed by 2 guard Each hole is open & closed by 2 guard cells cells

Stoma positionStoma position

Stoma is a small holeStoma is a small holeIts size is controlled by 2 guard cells

closed open

Stoma function is for gas Stoma function is for gas exchange in the leafexchange in the leaf

Carbon dioxide

oxygenGuard cell

Provided plant is photosynthesising

Stomata open and close at different times of the day

When it is light the plant needs CO2 for photosynthesis so the stoma open

At night (darkness) they close

Gas exchangeGas exchange

PHOTOSYNTHESISPHOTOSYNTHESIS

The The processprocess of photosynthesis is a of photosynthesis is a chemical reactionchemical reaction. .

It is the most important It is the most important

chemical reaction on our planet.chemical reaction on our planet.

PHOTOSYNTHESIS PHOTOSYNTHESIS EQUATIONEQUATION

PHOTOSYNTHESIS PHOTOSYNTHESIS EQUATIONEQUATION

Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

Describe PhotosynthesisDescribe Photosynthesis

The process of changing light energy to The process of changing light energy to chemical energy chemical energy

Energy stored as sugarEnergy stored as sugar Plants need light energy, COPlants need light energy, CO22, and H, and H22O O

Takes place in the Takes place in the chloroplastschloroplasts, using , using chlorophyllchlorophyll, the green pigment in plants, the green pigment in plants

What happens during What happens during photosynthesis?photosynthesis?

Carbon dioxide enters the leaf through holes Carbon dioxide enters the leaf through holes called called stomatastomata

COCO2 2 combines with the stored energy in the combines with the stored energy in the chloroplasts through a chemical reaction to chloroplasts through a chemical reaction to make glucosemake glucose

The sugar is moved through tubes in the leaf to The sugar is moved through tubes in the leaf to the roots, stems and fruits of the plantsthe roots, stems and fruits of the plants

Some of the sugar is used right away by the Some of the sugar is used right away by the plant for energy; some is stored as starch; and plant for energy; some is stored as starch; and some is built into plant tissuesome is built into plant tissue

ROOTSROOTS

ROOTS – function and ROOTS – function and structurestructure

Anchor plant in positionAnchor plant in position Absorb water and minerals Absorb water and minerals

from the soilfrom the soil Specialized cells to increase Specialized cells to increase

surface area for water intakesurface area for water intake Store food Store food

Types of RootsTypes of Roots

FibrousFibrous: several : several thin roots that thin roots that branch to form a branch to form a tangle masstangle mass

Ex. Grass, corn, Ex. Grass, corn, most treesmost trees

Types of RootsTypes of Roots

TaprootsTaproots: long : long thick main root thick main root and thin and thin branching rootsbranching roots

Ex. Carrots, Ex. Carrots, cacti,dandelionscacti,dandelions

Parts of a rootParts of a root

Epidermis: Epidermis: outermost layer outermost layer of the root that of the root that has hairs on ithas hairs on it

Parts of a rootParts of a root

Cortex: layer Cortex: layer just inside the just inside the epidermisepidermis Stores foodStores food Carries water Carries water

and minerals and minerals into vascular into vascular tissuetissue

Parts of a rootParts of a root

Root CapRoot Cap: : protects the root protects the root as it grows as it grows through the soilthrough the soil

Parts of a rootParts of a root

Growth tissueGrowth tissue: : just behind the just behind the root cap, where root cap, where new cells formnew cells form

Human uses for rootsHuman uses for roots

Food:Food: Carrots, beets, yamsCarrots, beets, yams Licorice, horseradish,and sassafras used as Licorice, horseradish,and sassafras used as

spicesspices

MedicineMedicine DyesDyes InsecticidesInsecticides

Parts of Parts of RootRoot

Root hairs

•Fragile parts of cells that grow from the main root

•They massively increase the surface area for absorption

STEM: Structure and STEM: Structure and FunctionFunction

Gets water and Gets water and nutrients from the nutrients from the roots to the leavesroots to the leaves

Holds the leaves up Holds the leaves up in the air so it can get in the air so it can get sunlight to make foodsunlight to make food

STEM: Structure and STEM: Structure and FunctionFunction

Vary greatly in Vary greatly in sizesize TrunkTrunk BranchesBranches TwigsTwigs

Types of StemsTypes of Stems

HerbaceousHerbaceous: have : have stems that are stems that are green and softgreen and soft

Ex. Sunflowers, Ex. Sunflowers, pea, tomatoes, pea, tomatoes, grass, abd grass, abd dandekionsdandekions

Types of StemsTypes of Stems

WoodyWoody: have : have stems that are stems that are hard and made of hard and made of woodwood

Ex. Roses, Firs, Ex. Roses, Firs, and Maplesand Maples

Structure of Woody stemStructure of Woody stem

Structure of Woody stemStructure of Woody stem

Bark: outermost layer Bark: outermost layer of stem of stem ToughTough WaterproofWaterproof Helps protect the Helps protect the

fragile tissue insidefragile tissue inside Inner part of the bark Inner part of the bark

is the is the phloemphloem

PhloemPhloem

Transports glucose and starch made Transports glucose and starch made during photosynthesis.during photosynthesis.

Structure of Woody StemStructure of Woody Stem

Vascular Cambium: Vascular Cambium: growth region of the growth region of the stemstem This is where xylem This is where xylem

and phloem are and phloem are producedproduced

Pith: Pith: Center of the Center of the stemstem Stores water and Stores water and foodfood

Stem RingsStem Rings

Each ring represents a year’s growth of Each ring represents a year’s growth of xylemxylem 1 ring = 1 year1 ring = 1 year

If a tree had 12 rings how old would it If a tree had 12 rings how old would it be?be?

12 years old12 years old