EUKARYOTIC PLANT CELLS

     I.  Membrane bound organelles separate chemical reactions    
         in space and time 

          A. Transcription -> Translation   ->   Modification ->
              Nucleus  -> Endoplasmic reticulum -> Golgi body ->

              Vesicles            ->   Plasma membrane  
              Transport & Storage -> Extracellular matrix 

          B. Glycolysis -> Krebs Cycle -> Electron Transport
             Cytoplasm  ->       Mitochondria

          C. Photosynthesis
             Chloroplast
     
     II. Structural shape and internal organization provided by
          Microtubules

     III. Cyclosis facilitated by Microfilaments

     IV. Extracellular Matrix = Cell Wall

          A. Composition = Cellulose microfibrils + Hemicellulose 
                + Pectic Substances in an Extensin Matrix

          B. Middle Lamella rich in Pectic Substances separates   
             adjacent cell walls

          C. Primary Cell Walls have random orientation of        
             microfibrils

          D. Secondary Cell Walls have oriented layers of         
             microfibrils and contain Lignin at maturity

      V.  Structural continuity through extracellular matrix 
          between adjacent cells via 

          A. Plasmadesmata (PD) in living cells
     
               1.  Endoplasmic reticulum - Desmotubule
               2.  Plasma membrane - Outer Membrane of PD

          B. Pits in dead cells

PLANT CELLS ARE CLASSIFIED ON BASIS OF COMBINATIONS OF THREE      
     CHARACTERISTICS

     I.  Components of Cytoplasm

          A. Presence of all organelles
          B. Lacking nucleus, mitochondria, chloroplasts
          C. Completely lacking

     II. Characteristics of Cell Wall

          A. Primary - thick vs. thin
          B. Primary + Secondary - Types of Pits

     III. Three Dimensional Geometry 

          A. Isodiametric
          B. Cuboidal
          C. Elongated

PLANT TISSUES CAN BE CLASSIFIED ON BASIS OF CELL ASSOCIATIONS

     I. Simple Tissues = only one cell type

          A. Primary Meristematic 

               1. IA-dense protoplasm, IIA-thin, IIIA
               2. Produce all other cell types

          B. Secondary Meristematic

               1. IA-vacuolated, IIA-thin, IIIA,B,C
               2. Produce secondary vascular tissue and cork

          A. Parenchyma 
               
               1. IA, IIA-thin, IIIA
               2. Basic Support, Photosynthesis, Storage

          B. Collenchyma 

               1. IA, IIA-thick, IIIC
               2. Flexible Support during growth

          C. Sclerenchyma 

               1. IC, IIB, IIIA,B,C
               2. Inflexible support after growth, protection

     II. Complex Tissues = two or more cell types

          A. Xylem - Conduct water + elements (Transpiration)
                   - Structural support 
                    
               1. Parenchyma

               2. Tracheids (IC, IIB, IIIC-spindle shaped)
               
               3. Vessel Elements (IC, IIB, IIIC-cylindrical;
                    joined end to end to form Vessels)


          B. Phloem - Conduct water + Photosynthate (Translocation)

               1. Parenchyma (companion cells)

               2. Sieve Tube Elements (IB, IIA, IIIC-cylindrical;
                     joined end to end to form Sieve Tubes

          C. Primary Epidermis - Protection + Gaseous Exchange

               1. Ground parenchyma (IB-no chloroplast, IIA-with  
                     wax on outside cell wall, IIIB)

               2. Guard Cells (IA, IIA-with wax and stomatal pore 
                     between pairs, IIIB-bean or bone shaped)

               3. Trichomes (IA, IIA, IIIC)

          D. Periderm - Protection + Gaseous Exchange 

               1. Cork (IB, IIB-with Suberin and no air spaces,   
                        IIIB)

               2. Lenticils (IB, IIB with air spaces, IIIB)
                    
               3. Non functional Phloem 
          
PLANT TISSUES CAN BE CLASSIFIED ON THE BASIS OF ORIGIN

     I. Primary Tissues - derived from primary meristems

     II. Secondary Tissues - derived from secondary meristems

PLANT TISSUE SYSTEMS CAN BE CLASSIFIED ON BASIS OF FUNCTION

     I. Supportive
     
     II. Protective

     III. Absorptive

     IV. Photosynthetic

     V. Transport

     VI. Storage

     VII. Reproductive