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Chapter 22 (concepts (gymnosperm (naked ovules, pine cones), angiosperm…

- - - - tube like closed structure
- - - - stems was protostele
  - - - pith surrounded by primary xylem
    - - were heterosporous
  - - - produced one megaspore
        
        produced one large megaspore
        
        three small aborted cells
      - mother cell
      - surrounded by layer of tissue
        
        integument
        
        projected upward
      - micropyle
        
        hole in integument
        
        allows sperm cells to swim to egg
      - pollen chamber
        
        space at top of megasporangium
        
        microspores settle
- - - - cycads
      - extant
    - - cycadeoids
      - all extinct
    - - seed fern
      - all extinct
  - - - form a grade not clade
    - - manoxylic
      - around stem
        
        pteridosperm thick cortex
        
        distinct radial plates
        
        inner cortex
        
        secretory ducts
    - - large, compound, planar
- - - - located below megasporophylls
- - - - simple needles or scales
    - - simple
      - one or two veins running dow the center
      - endodermis tissue
        
        transfusion tissue
        
        transfusion parenchyma cell
        
        transfusion tracheids
        
        transfusion parenchyma
        
        intermixed with tracheids
        
        two cell types
        
        form complex 3D pattern
        
        facilitates transfer of material
        
        between ordinary vascular tissue & mesophyll tissue
    - - thin and tall
      - contain ray parenchyma
        
        ray tracheids
    - - produce thick tough bark
      - provides protection from forest fires
    - - tiny papery leaves
      - short shoots
        
        long needle leaves
    - - pollen cones
      - single short branched axis
        
        bears microsporophylls
    - - compound cone
      - shoot with axillary buds
      - cone bracts
        
        short axis leaves
    - - microscopic
      - megasporophylls are fused laterally
        
        ovuliferous scale