Ch 25 Plant Organization

Document Sample
Ch 25 Plant Organization Powered By Docstoc
					             Plant Organization


             Chapter 25

Chapter 25    Plant Structure and Organization   1
                         Outline
                                             Stems
   Roots
                                                 Organization
       Organization
                                                 Diversity
       Diversity
                                             Leaves
                                                 Organization

                                                 Diversity




Chapter 25             Plant Structure and Organization          2
             Organization of Roots
   Root Apical Meristem
       Located in the root tip
       Protected by the root cap
   Primary Meristems are in the zone of cell
    division
       Provide   cells for the zone of elongation
   Zone of Maturation contains fully
    differentiated cells
       Where   hairs begin

Chapter 25             Plant Structure and Organization   3
                 Tissues of Eudicot Root
   Epidermis
       Outermost, single layer of cells
       Epidermal cells in the zone of maturation have root
        hairs
   Cortex
       Insidethe epidermis
       Large and irregular shaped cells inside the epidermis

                Spaces btwn cells allow water & minerals to move within the
                 cortex
       Have        starch granules for food storage



Chapter 25                      Plant Structure and Organization               4
             Tissues of Eudicot Root
   Endodermis
       Single  layer btwn the cortex and inner vascular
        cylinder
       Cells tightly packed surrounded by the Casparian
        Strip
       Allows for regulating water and minerals entering the
        vascular cylinder.
   Vascular Tissue
       Pericycle first layer of cells that will reproduce into
        specialized cells as you move inward.
       Xylem in a star shape
       Phloem found between points of the xylem
       Undergoes primary and secondary growth

Chapter 25                Plant Structure and Organization        5
             Eudicot Roots




Chapter 25     Plant Structure and Organization   6
       Branching of Eudicot Root




Chapter 25      Plant Structure and Organization   7
Organization of Monocots Roots
 Ground tissue of roots pith surrounded by
  a vascular ring
 Have same growth zones as eudicot roots
 Do not under go secondary growth




Chapter 25     Plant Structure and Organization   8
             Monocot Root




Chapter 25     Plant Structure and Organization   9
                   Root Diversity
   Primary root (taproot) - Fleshy, long single root,
    that grows straight down

       Stores   food

   Fibrous root system - Slender roots and lateral
    branches

       Anchors   plant to soil

   Adventitous roots - Roots develop from organs
    of the shoot system

       Prop   roots
Chapter 25              Plant Structure and Organization   10
                   Root Diversity
   Haustoria:
       Rootlikeprojections that grow into host plant
       Make contact with vascular tissue and extract
        water and nutrients
   Mycorrhizas:
       Associations  between roots and fungi
       Assist in water and mineral extraction

   Root nodules - Contain nitrogen-fixing
    bacteria

Chapter 25             Plant Structure and Organization   11
             Root Diversity




Chapter 25     Plant Structure and Organization   12
                 Organization of Stems
   Shoot apical meristem
       Produces  new cells that elongate and
        increase stem length
       Protected by terminal bud
              Enveloped by leaf primordia
              Specialized primary meristems
                  Protoderm
                  Ground Meristem
                  Procambium




Chapter 25                   Plant Structure and Organization   13
             Woody Twig




Chapter 25    Plant Structure and Organization   14
 Shoot tip and Primary
 Meristems




Chapter 25   Plant Structure and Organization   15
                    Herbaceous Stems
   Mature nonwoody stems exhibit only
    primary growth

       Outermost         tissue covered with waxy cuticle

       Stems        have distinctive vascular bundles

                Herbaceous eudicots - Vascular bundles arranged
                 in distinct ring

                Monocots - Vascular bundles scattered throughout
                 stem

Chapter 25                   Plant Structure and Organization   16
        Herbaceous Eudicot Stem




Chapter 25     Plant Structure and Organization   17
             Monocot Stem




Chapter 25    Plant Structure and Organization   18
                  Woody Stems
   Woody plants have both primary and
    secondary tissues

       Primary  tissues formed each year from
         primary meristems

       Secondary  tissues develop during first and
         subsequent years from lateral meristems



Chapter 25            Plant Structure and Organization   19
               Woody Stems
   Woody stems have no vascular tissue,
    and instead have three distinct regions


       Bark



       Wood



       Pith
Chapter 25        Plant Structure and Organization   20
        Secondary Growth of Stems




Chapter 25      Plant Structure and Organization   21
                            Bark
   Bark of a tree contains cork, cork cambium, and
    phloem

   Bark can be removed, but it is harmful to the
    plant due to lack of organic nutrient transport

   Cork cells are impregnated with suberin

       Gas   exchange is impeded except at lenticels


Chapter 25            Plant Structure and Organization   22
                            Wood
   Wood is secondary xylem that builds up year
    after year

       Vascular   cambium dormant during winter

       Annualring is made up of spring wood and
         summer wood

   In older trees, inner annual rings, heartwood, no
    longer function in water transport


Chapter 25             Plant Structure and Organization   23
        Three-year-old Woody Twig




Chapter 25      Plant Structure and Organization   24
             Tree Trunk




Chapter 25   Plant Structure and Organization   25
             Stem Diversity
   Stolons:
       Above-ground horizontal stems
       Produce new plants when nodes touch the
        ground
   Rhizomes:
       Underground   horizontal stems
       Contribute to asexual reproduction
       Variations:
              Tubers - Enlarged portions functioning in food
               storage
              Corms - Underground stems that produce new
Chapter 25                    the next season
               plants during Plant Structure and Organization   26
             Stem Diversity




Chapter 25     Plant Structure and Organization   27
             Leaf Organization
   Epidermal Tissue (top and bottom layer)
    Bear protective hairs or glands with
      irritating substances
    Has an outer, waxy cuticle
    Stomata allow for gas exchange.
         Monocot (top & bottom)

         Eudicot (bottom only)

         Guard cells regulate water loss.



Chapter 25       Plant Structure and Organization   28
             Leaf Organization
   Mesophyll tissue(middle)
    Palisade Mesophyll (elongated cells)
    Spongy Mesophyll (irregular cells)
       Surrounded by air spaces that
        maximize the amount of gas
        exchange possible
    Contain chloroplasts for photosynthesis



Chapter 25       Plant Structure and Organization   29
             Leaf Organization




Chapter 25       Plant Structure and Organization   30
                  Leaf Diversity
   Blade of a leaf can be simple or compound


   Leaves are adapted to environmental conditions.


       Shade    leaves


       Spines


       Climbing   leaves
Chapter 25                Plant Structure and Organization   31
             Classification of Leaves




Chapter 25          Plant Structure and Organization   32
             Leaf Diversity




Chapter 25    Plant Structure and Organization   33

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:10
posted:12/11/2011
language:
pages:33