PLANT TISSUESPLANT TISSUES

1) Dermal Tissue1) Dermal Tissue Form outermost layer of plant (like Form outermost layer of plant (like

the skin)the skin) Protects plantProtects plant Allows substances in and out Allows substances in and out

through the stomata (will discuss through the stomata (will discuss details later)details later)

2) Vascular Tissue2) Vascular Tissue Makes the transport system that moves Makes the transport system that moves

minerals, water and other chemicals minerals, water and other chemicals around plant (like circulatory system)around plant (like circulatory system)

2 types of vascular tissue2 types of vascular tissue XylemXylem transports water and minerals transports water and minerals

UPUP from roots from roots Made up of dead tissue Made up of dead tissue basically hollow basically hollow

tubestubes PhloemPhloem transports water and sugar transports water and sugar

produced by photosynthesis up and produced by photosynthesis up and down down Made up of living tissueMade up of living tissue

3) Ground Tissue3) Ground Tissue Form the bulk of the plantForm the bulk of the plant Wide variety of functions:Wide variety of functions:

**Where photosynthesis **Where photosynthesis occurs**occurs**

Provide structural supportProvide structural supportStorage Storage

In rootIn root

In StemIn Stem

copy from pg.130 into notescopy from pg.130 into notes

Tissues Working Tissues Working TogetherTogether

Plants need to perform photosynthesisPlants need to perform photosynthesis

COCO22 + H + H22O + light energyO + light energy C C66HH1212OO66 + O + O22

Plants need to be able to get reactants (carbon Plants need to be able to get reactants (carbon dioxide and water) to the chloroplasts!dioxide and water) to the chloroplasts!

LightLight

Chloroplasts: located in palisade layer Chloroplasts: located in palisade layer and spongy mesophylland spongy mesophyll

Palisade layer: closely packed to capture Palisade layer: closely packed to capture lightlight

Spongy mesophyll: loosely packed to Spongy mesophyll: loosely packed to allow movement of gasesallow movement of gases

Carbon DioxideCarbon Dioxide

Enter through stomata and then move Enter through stomata and then move through spongy mesophyllthrough spongy mesophyll

WaterWater

Water is absorbed into roots (via root Water is absorbed into roots (via root hairs)hairs)

Water is transported from roots to leaves Water is transported from roots to leaves by xylemby xylem

Waxy cuticle and stomata prevent too Waxy cuticle and stomata prevent too much water lossmuch water loss

STOMATASTOMATA

Openings in the dermal tissue that:Openings in the dermal tissue that: Control amount of COControl amount of CO22 entering leaf. entering leaf.

Control amount of water lostControl amount of water lost

Opening and Closing:Opening and Closing: Each stoma is bordered by two guard Each stoma is bordered by two guard

cellscells

Able to open and close by changes Able to open and close by changes in amount of water in guard cellsin amount of water in guard cells

Water flows in to guard cells, they Water flows in to guard cells, they swell and it causes stoma to openswell and it causes stoma to open

Water flows out from guard cells, Water flows out from guard cells, they shrink and it causes stoma to they shrink and it causes stoma to closeclose

Factors Affecting Stomatal Factors Affecting Stomatal Opening Opening

As Water Loss increases stomata closeAs Water Loss increases stomata close Carbon dioxide concentration increasesCarbon dioxide concentration increases

stomata closestomata close Light: stomata open in light and close in Light: stomata open in light and close in

darkdark Temperatures higher then 30Temperatures higher then 3000C to 35C to 3500C C

result in stomata closingresult in stomata closing Also show a daily rhythmAlso show a daily rhythm