chapter 5 notes – pages 90 - 107 1 white oak, illinois state tree white oak trees have bark that...
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Plant Tissues and the Multicellular Plant Body
Chapter 5 Notes – Pages 90 - 107
White Oak, Illinois State Tree
White oak trees have bark that is off-whitish to ashy gray in color. It can be very scaly and platelike. Older trees often have patches of nearly smooth bark.
Rounded lobes & Acorns
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Today, we are going to learn aboutPlant Body Structure Plant Life SpansGround Tissue SystemVascular System TissuesDermal Tissue SystemPlant GrowthPrimary & Secondary growth
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Plant Body StructureAll plants have the same basic body planPlant body is organized into 2 Systems
Root System (underground portion) Tap Root Branch Roots
Shoot System (aerial portion) Stem Leaves Flowers & Fruits *only in flowering plants*
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Figure 5-1
Branch roots
Developing fruit
Nodes (areas of leaf andaxillary bud attachment)
Axillary bud
Flower
Internode (area betweenadjacent nodes)
Shootsystem
Rootsystem
Rosette ofbasal leaves
Petiole Blade
LeafStem
Taproot
Fig. 5-1, p. 92
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Plants grow below & above groundPlants need resources from both
environmentsBelow ground
Dark Moist Nutrients / Dissolved minerals Roots anchor the plant to the ground Absorbs Water
Above ground Sunlight Carbon Dioxide
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2 Different types of Plant BodyHerbaceous Plants
Do not develop persistent woody parts above ground
Typically green exteriorDie after growing season
Woody Plants Develop persistent woody parts above groundPersist after growing season
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Plant Life SpansAnnuals
Herbaceous plants that grow, reproduce, & die in 1 year or season
Examples: Corn, sunflowers, most food garden plantsBiennials
Herbaceous plants that take 2 years to complete their life cycles
Examples: Carrots, cabbage, celery, & parsleyPerennials
Woody or herbaceous plants that live for more than 2 yearsAerial shoots of herbaceous perennials die each winterGrow back in SpringExamples: All trees, rhubarb, onions, asparagus, iris
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Cells & Tissues of the Plant BodyThe cell is the basic structural and functional
unit of plantsPlant cells are organized into tissuesTissues are groups of cells that form a
structural and functional unitSimple tissues – 1 kind of cellComplex tissues – 2 or more kinds of cells
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3 Plant Tissue SystemsTissues are organized into 3 tissue systems
1. Ground Tissue System Most of the plant body Functions include photosynthesis, storage,
structural support
2. Vascular tissue system (think of veins) The plumbing system of the plant Extends throughout the plant body Conducts water, dissolved minerals, and food
(dissolved sugar)
3. Dermal Tissue System Strengthens & Supports the plant This system covers the plant body (like skin)
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1. Ground System TissueComposed of 3 Simple Tissues
1. Parenchyma Cells have thin primary cell walls Unspecialized – Can differentiate into other
kinds of cells Functions: Photosynthesis, storage, & secretion Most common type of cell & tissue in plants
2. Collenchyma Cells have unevenly thickened primary cell walls
3. Sclerenchyma “Sclero” means “Hard” Cells have both primary cell walls & thick
secondary walls Provides support to plant body
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2. Vascular Tissue SystemComposed of 2 Complex Tissues
Xylem Conducts water and dissolved minerals Transfers from Roots stem & leaves Composed of 2 types of cells
Tracheids – chief water conducting cells Vessel Elements – have holes in end cell walls
Phloem Conducts food throughout the body Composed of 4 types of cells
Sieve-tube elements – highly specialized cells Companion cells Phloem fibers (long tapered cells) Phloem parenchyma cells
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EpidermisOutermost layer of herbaceous plant, usually
one cell thickCovers the primary plant body (leaves, young
stems and roots) Prevent Water Loss
Secretes a waxy cuticle Stomata regulates gas exchange using guard
cellsComposed of 2 types of cells
Guard cellsTrichomes
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PeridermReplaces epidermis in woody plantsForms the protective, outer barkOutermost layer of cells covering a woody
stem or root
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Periderm
Geranium
Cortex(interior of stem)
Exteriorenvironment
Remnantsof epidermis
Cork cellsCork cambium P
eri
derm
Corkparenchyma
Fig. 5-10, p. 103
Primary GrowthIncrease in stem and root lengthResult of activity of apical meristems at the
tips of roots and at the buds of stems Apical Meristem
An area of cell division at the tip of a stem or root in a plant; produces primary tissues
Bud A dormant embryonic shoot that eventually
develops into an apical meristem
Secondary GrowthIncrease in stem and root girthSecondary growth is localized, typically as
long cylinders of active growth throughout the lengths of older stems and roots
Lateral MeristemAn area of cell division on the side of a
vascular plantGives rise to secondary tissues2 Lateral Meristems
Vascular Cambium Cork Cambium
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