Slide 1Main SectionsSlide 33 main plant organs: Root3 main plant organs: Stem3 main plant organs: LeafAnatomy terms to learn on your ownSlide 83 Tissue systems3 Tissue systemsPlant developmentMeristemsSlide 13Slide 14Review QuestionsSlide 16Slide 17Slide 18Slide 19Plant Structure & Development ILecture 10LIFE103 von FischerMain Sections•Anatomy–Structures–Cells•Growth–Tissues–cellsFig. 35-23 main plant organs: Root•Roots– anchors the plant in place– absorb minerals & water– store carbohydrates•Taproot: main vertical root – present in most gymnosperms & eudicots– deeply penetrates•Lateral roots: branch off taproot•Root hairs: grow off lateral roots–Finer roots- access water & nutrients–Have very high surface area3 main plant organs: Stem•Stalk upon which leaves grow –Shoot system: leaves & stem•Nodes: point on stem where leaves are attached•Internodes: stem segments b/w nodes•Axillary bud: structure that can form a lateral shoot–Growth inhibited by proximity to apical bud •Apical (terminal) bud: elongation point of a growing shoot–Composed of developing leaves, nodes & internodes3 main plant organs: Leaf•Main photosynthetic organ•Blade: flattened structure/ lamina•Petiole: small “leaf stem” that joins the leaf to the stem @ the nodeAnatomy terms to learn on your own•Roots–Prop roots- support the tall, top-heavy trees; Ex. Hala Trees– storage roots- store food & water; Ex. Beets•Stems–Rhizomes- horizontal shoot that grows just below the surface– bulbs- vertical, underground shoots consisting of bases of leaves that store foods–Stolons- horizontal shoots (“runners”) that grow along the surface; enable plant to reproduce asexually– tubers- enlarged ends of rhizomes/stolons specialized for storing food•Leaves–Simple- a undivided blade w/ one segment– compound- a blade w/ multiple segments (leaflets)– doubly compound- leaflets divided into smaller leaflets–Tendrils- modified leaves/stems that uses a coil to bring plant closer to a support– spines- prickly modified leaves– bracts- modified leaves that surround a group of flowers; mistaken as petalsFig. 35-83 Tissue systems•Dermal tissue: –Epidermis: outer protective layer–Cuticle: waxy coating over epidermis–Example: root hair = extended epidermal cells•Vascular tissue: long-distance transport of materials b/w roots & shoots–Xylem: conducts water & minerals from roots to shoot –Phloem: transport sugars–Stele (“pillar”): vascular tissue (collectively) of stem or root3 Tissue systems•Ground tissue: in b/w the dermal & vascular tissue layers–Pith: inside of (internal) vascular tissue in the stem–Cortex: outside of (external) vascular tissuePlant development•Differentiation: developmental changes in a cell’s cytoplasm, organelles and/or cell wall during development special tissue cells making up the ground tissue system: functions = storage, support & metabolic processesa. Parenchyma- performs most of metabolism, synthesizes and stores organic products; thin-walled; ability to divideb. Collenchyma- unevenly thickened-walled; support young, growing parts of the plantc. Sclerenchyma- thick, lignified walls; support mature, non-growing parts of plant (fibers & sclereids)Meristems•Meristem: (“cell division”) tissue that’s perpetually embryonic•Apical meristem: located @ apical bud of shoots & roots–Allows “Primary Growth (1⁰)” in length•Lateral meristem: allows “Secondary Growth (2⁰)” stem thickening in woody plants–Vascular cambium: adds layers of 2ndary xylem (wood) & phloem~ producing vascular tissue laterally–Cork cambium: replaces epidermis (1⁰ growth) w/ tough periderm (2⁰ growth)~ producing dermal tissue laterallyFig. 35-11Shoot tip (shootapical meristemand young leaves)Lateral meristems:Vascular cambiumCork cambiumRoot apicalmeristemsPrimary growth in stemsSecondary growth in stemsEpidermisCortexPrimary PhloemPrimary XylemPithPeridermCork CambiumCortexPrimary Phloem2ndary PhloemVascular Cambium2ndary XylemPrimary XylemPithAxillary budMeristemFig. 35-12Review Questions•Which of the following places is a meristem NOT found? ~ ANSWER: Root Hair•Where are meristems found? ~ANSWER: root tip, shoot tip, cork cambium & vascular cambium•If a sugar molecule is in the apoplastic space, how does it back into the symplasm? ~ ANSWER: cotransported w/ protons (H+)•Where is the force generated that moves water from the soil into the roots? ~ ANSWER: microfibrils in the mesophyll•Stomata close under draught stress. How does this happen? ~ ANSWER: Potassium ions (K+) are pumped out of guard cells & water follows by osmosis•This process signals a hormone to bind to a receptor? ~ANSWER: Transduction•What determines the germination of moistened lettuce seeds? ~ANSWER: color of light the seeds are last exposed to (last exposed to Red Light)ApicalmeristemRoot capVascular cylinderCortexEpidermisRoot HairZone ofDifferentiationZone ofElongationZone of