1. Topic
2. Topic
3. Topic
4. Root Stems
   1. Tap Root
      1. Topic
      2. primary root
      3. deep and thin
   2. Lateral Root
      1. develops from anoother root
      2. secondary root
   3. Adventitious Root
      1. Topic
      2. shallow but wide
   4. Mature Root
      1. apical meristem
         1. grows in this area
      2. root cap
         1. protects apical meristem
      3. area of elongation
         1. above meristematic tissue
         2. new cells develop
            1. forms xylem
            2. forms phloem
      4. root hair region
         1. above area of elongation
         2. water absorption
         3. above area of differentiation
5. Tissues
   1. Epidermis
      1. no cuticle
         1. water absorption
      2. no guard cells = no stomata
      3. develop in root hairs
      4. unicellular
      5. waxy cuticle
      6. prevents loss of water
   2. Cortex
      1. endodermis
         1. controls passage of water
         2. brick shaped
         3. Casparian bands
      2. parenchyma (mainly)
      3. sclerenchyma
      4. collenchyma
      5. starch sheet
         1. inner layer
      6. produces food
         1. young stem
      7. stores food
         1. older stem
      8. protect and strengthen
   3. central cylinder
      1. pericycle
         1. in endodermis
         2. can develop into..
            1. lateral roots
            2. vascular cambium
            3. cork cambium
   4. Vascular
      1. cross / star shaped
         1. in centre
         2. xylem forms cross/star
            1. eventually becomes central cylinder
            2. transport of water
         3. phloem in invaginations
            1. becomes part of bark
   5. Vascular Bundle
      1. cambium
      2. Xylem
      3. Phloem
6. Anatomy of stems
   1. what do they do?
      1. mechanical support
      2. bear leaves
         1. to receive appropriate sunlight
      3. flowers
         1. favourable positionfor polination
      4. distribution of fruit
      5. transport
         1. water & Minerals
      6. distribute
         1. organic food
   2. grow longer in apical tips
      1. prmiary growth
   3. Cambium
      1. secondary thickening
      2. cork cambium
         1. bark or cortex
   4. lateral buds
      1. new stems, leaves, flowers
7. Development if Bark
   1. Cork Cambium
      1. beow epidermis
      2. produces
         1. cork cells to the outside
   2. Cork Cells
      1. small and flat
      2. few/no intercellular space
      3. suberin
      4. waterproof
      5. protect stem
         1. loss of water
         2. mechanical injury
   3. Older Stems
      1. cortex & Phloem visible
         1. shiny & silky
      2. Phloem
         1. no function