General Vascular Plant Structures & Growth PDF

General Vascular Plant Structures & Growth  Basic Organization Plants typically divided into roots and shoots Roots responsible for: below -...

General Vascular Plant Structures & Growth  Basic Organization Plants typically divided into roots and shoots Roots responsible for: below - ground keeps plants secured Anchoring plant -main purpose nitrogen's phoshoms Collecting water & minerals from soil - ex. help winter get turn - Storing excess carbohydrates or other materials Shoots (stems & leaves) responsible for: - above ground Collecting CO2 and light for photosynthesis Height and support structures helps get plants grow > - to taller Sexual reproduction flowers ex. Defense experience major threats (nerbivores) - stems  have both ? Xpossible for plants to Roots Form from initial primary root during seed germination be potential to - tap root or lateral ex need > Taproot grows vertically and primarily used for stability (an anchor) -. Fiberous root Lateral roots grow horizontally and primarily used for absorption (large ex. grass- > surface area) SA more more = Root hairs and mycorrhizae further enhance absorption by maximizing surface area absorb. > - fungi (symbiant) in soil ; inc surface area in. exchange for food Cap root ( lateral root (mycorrhizae system  hold up leaves Shoots (Stems) purpose - to conduct side growth photosynthesis & elongation- Leaf-bearing structure; supports leaf functions (photosynthesis, transport, reproduction) Alternating nodes (leaf attachments) and internodes (stem space between nodes) Growth at apical bud (tip) and axillary buds (at nodes) Some photosynthesis possible only contains - "green" areas at chlorophyll Co that Some specialized subterranean stems used for asexual reproduction or food storage (ex: ② eX rhizomes) ↳ clones can be ground - created above or below casti stem do photosynthesize Ginger root · can be predatory > - ex. Venus flytrap Shoots (Leaves) ↳ major pmpose photosynthesis O Primary role: photosynthesis (CO2 + H2O -> cool down or C6H 12O 6CO ++ 6H 26 O2)2O + light ⇨ 6O2 + C6 H12O6- conserve #20 Secondary roles: thermoregulation, - Ctrl the defense rate of water loss changing by the Orientation Highly varied to suit plant needs, but of leaves generally composed of blade and petiole (specialization of leaves  Plant Tissues - 3 types tissues cells > - - organs Tissue: groupings of cells that perform similar functions Plant tissues form tissue systems that are continuous and are classified into three categories: Type #1 Dermal (outer) Epidermis (’skin’ to defend against damage, invaders) succulents good for not Cuticle (waxy coating to minimize water loss) ex. protects against Periderm (only in woody tissue, replaces epidermis) I UV Guard cells (control stomata) open close pores. - Trichomes (specialized defense tissues) Loften on stems; can be on leaves "hair" on plant prevent ants crawing of irritant  Plant Tissues Con’t Vascular (transport) Xylem (transports water, dead Hollow - tubes that carry H20 dissolved minerals from roots to shoots) Phloem (transports sugars throughout the plant) Ground (not dermal or vascular) fills in spaces I s Vascular btwn dermal Pith (internal to vascular tissue) I deep win- plants Cortex (external to vascular tissue)  Plant Growth & Development "yma" ground Plant cells go through tissue differentiation to specialize for a particular role Heals plant- Parenchyma: metabolic functions Photosynthesis, storage, fruits, repair Collenchyma: support with flexibility flexibility important - for direction path Found in young shoots or of growth Sclerenchyma: support with rigidity Woody tissue, seed coats, hemp fibers ex apple seeds. + lex x of z types support o brigid  Plant Growth & Development Con’t meristem - located to grow O continues - w/ limitations Plants exhibit indeterminate growth: grow throughout life STEM cells - Meristems: undifferentiated tissues capable of of plants division, allowing continuous growth Certain features do have determinate growth (leaves, thorns, flowers) Apical meristems: responsible for primary growth getting taller (elongation); located in root and shoot tips longer Leaf scars and bud scars show growth from previous season in trees (perennials) - pausing Lateral meristems: responsible for secondary growth growth (widening); found along lengths of roots and shoots during winter Woody tree rings arise from growth cycles of cambium ( used to support heavier features above more mass required · = more support  Primary Growth (Elongation) Roots: Root cap (protection) "plant helmet" - Zone of cell division (produce new cells) Zone of elongation (where cells elongate for growth) of zone - Zone of differentiation (where cells maturation mature/specialize) cellsoff genes to specialize turn Protoderm (dermal tissue; forms epidermis, root hairs) Ground meristem (ground tissue) ( Endodermis (vascular tissue; forms xylem/phloem) plants can stretch out cells to grow root tip  Primary Growth (Elongation) roots Shoots: - similar to now grow elongation differentiation · zones of cell division , , stem has to Growth occurs at apical meristem (‘tip’) get wider to Apical dominance: apical bud represses apical elongation meristem in nearby axillary buds - support If apical buds are removed, axillary buds form lateral shoots (‘bushier’ appearance) controls development - of stem Undergo similar lengthening as roots Division and differentiation leads to protoderm (forms dermal tissue), ground meristem (forms ground tissue), and procambium (forms vascular tissue) protoderm > - dermal ground meristem > - ground Vascular procambium > - Primary Growth Con’t bacteria fungi predators protects against , Epidermis often thin with waxy cuticle UV , - Ground tissue largely parenchyma cells (like in roots) BUT collenchyma cells also present (additional support necessary for height) Vascular tissue collects into vascular bundles Near soil line vascular bundles form a single vascular cylinder Higher up the stem vascular bundle are largely oriented along the stem surface Either in a ring structure (eudicots) or scattered (monocots) => 2 forms of vascular bundles ① ② Leaves - purpose capturing light for photosynthesis Originate at nodes from leaf primordia Vary widely in features depending on environment, but composed of: Dermal tissue = waxy cuticle over thin epidermis, punctuated with stomata Ground tissue = mesophyll (parenchyma used in photosynthesis) Vascular tissue = veins surrounded by bundle sheath in mesophyll connect to vascular tissue of stem Secondary Growth (Width) plants want to taller to get get access to sunlight Primarily associated with woody plants Allows for dramatic height by supporting stem against gravity Width increases as vascular cambium adds secondary xylem (wood) and secondary phloem and cork cambium adds tough, waxy cells to defend against water loss, insects, and pathogens Wood gets additional strength from lignin Tree rings are alternations in cell type: In spring water is abundant & secondary xylem has large, thin-walled cells to transport water (‘early wood’; later season growth has thicker cell walls to support growth but transport less water (late wood) Crade off : thicker walls = less water Woody Tissue Secondary xylem in stems organized into heartwood (deeper, older, non-active xylem) and sapwood (newer, more superficial rings of active xylem) Bark is found external to the vascular cambium; contains secondary phloem and cork Maple syrup is made by concentrating sap collected from relatively thin layer of secondary phloem Plant Development Development: series of changes leading to cells forming tissues, organs, and overall organisms In plants, development relates to: Growth (increase in size) Establish polarity (top vs bottom) and direction/amount of cell division Morphogenesis (control of shape/organization) Establish tissue layers/orientation Differentiation (expression of genes leading to particular cell types) All cells have the same information, but only express necessary genes for their role