1. CHAPTER 35 PLANT FORM WOOOOO!!!!!!!

2. Meristems: They elaborate the plant body after germination
- act as stem cells for plants- rapidly divide into differentiated cells that make up the plant body
- two types:
    - apical meristems= elongate the root and stem of plant
    - lateral meristems= produce and increase in girth
        - only present in vascular plants (shrubs and trees)

3. Apical Meristems
 - located at the tips of stems and roots
-  after germination, meristems produce primary tissues which becomes the primary plant body (soft shoots and roots) 
- develop into three types of embryonic tissue systems
    - protoderm- forms the epidermis
    - procambium- produces primary vascular tissue
    - ground meristem- differentiates further into ground tissue
(Think of the plant as if its still an embryo, these are the developmental stages of plant life)

5. Lateral Meristems
- lateral meristems produce what is called secondary growth= most of the trunk, branches, and older roots of trees
- has the most dramatic effect in woody plants which have two lateral meristems
    - cork cambium- produces the cork cells of the outer bark
    - vascular cambium- produces secondary vascular tissue and lies between the xylem (wood) and phleom (cells close to woods surface) 
- interesting fact: removing the bark of a tree damages the phloem and may eventually kill the tree

6. Organization of the Plant Body
-- coordination of primary and secondary growth produces an adult plant
- plants do not have a fixed size and vary between plants, even of the same species
- number, size, structure, and location of leaves is dependent on plant environment
- vascular plants have a root system ( grounds them and provides the plant with ions) and a shoot system (the stem, leaves, flowers, and fruit)
- nodes and internodes on the shoot develop axillary buds that create new growth -

8. Types of Plant Tissue: Dermal Tissue
-Epidermal cells cover all the primary plant body
- a number of specialized cells occur at the epidermis
- guard cells flank the stomta (epidermal openings) 
    - contain chloroplast
    - stomata only occur on the epidermal tissue of leaves
    - exchange of CO2 and O2 occur at stomata
- Trichomes- hair like outgrowths of the epidermis (the "fuzzy stuff" on stems and leaves)
    - keep leaf surfaces cool and reduce transpiration 
    - some secrete sticky or toxic substances
- Root hairs- occur at the tips of young roots
    - keep the root in close contact with soil and increase absorption efficiency 
- in vascular plants, the cork cambium produces bark which replaces the epidermis

11. Types of Tissue: Ground Cells
- Parenchyma cells: most common type of cell, less specialized, mainly store food and water in large vacuoles
- Collenchyma cells: relatively flexible, provide support for plant organs so they can bend without breaking (the strings of celery)
- Scelrenchyma cells: two types
    - fibers= long slender cells grouped in strands
    - sclereids= form in branched bundles
- cell wall of scelrenchyma cells contain ligin- branched polymer that causes the cell wall to become rigid

13. Types of Tissue: Vascular
- xylem cells: principle water conducting tissue of plants
- a combination of dead hollow cells that make vessels and trachieds
- water and other ions travel from the roots through the xylem to the leaves and diffuses as water vapor out of the stomata
- Phloem cells: principal food conduction tissue of plants
- carried out by sieve cells and sieve-tube members
- sieve-tube memebers form sieve tubes and each cell is pared with a parenchyma cell (called compaion cells)
-connected by plasmodesmata- which supplies the plant cells with organic materialsr

14. Root Structure -there are three types vegetative organs in plants;
       - roots, stems, and leaves
-there are four parts recognized in developing roots;
        -root cap, zone of cell division, the zone of elongation,        
               and zone of maturation   
-apical initials divide the cells that divide and end up on the tip become root cap cells
-the other cells divide in opposite directions and pass through the three zones then they are fully differentiated
      

16. The Root Cap
-the root cap consist of two types of cells; columella cells (the inner cells) and root cap cells (the outer cells)
-the root cap cells are continuously replenished by the root apical meristem
-there are golgi bodies in the root cap cells that secretes a slimy substance, this helps the root through the soil. It also helps with the growth of nitrogen-fixing bacteria
-the root cap also functions as the perception of gravity
-the inner (columella) cells are very specialized     
         -they have endoplasmic reticulum in the nucleus and the periphery which is located in the middle or top of the cell
         -contain no large vacuoles
         -contain amyloplasts which form on the sides of the cells towards the pull of gravitiy        
        

17. The Zone of Cell Division
-apical meristem is located in the center of the root tip , it is shaped like a inverted concave dome
-cells divide every 12 to 36 hours at the edge of the dome
-these new daughter cells go to one of the three tissues; protoderm, procambium, or ground meristem
-in this section genes have been identified
-the inner cell layer regulates the flow of water, the outer cell layer acts as storage
-if a mistake occurs and a cell is not in the correct place the cell will develop according to the new postition

18. The Zone of Elongation
-the cells from the primary meristem become several times longer than they are wide, this causes the root to lengthen
-the vacuoles inside these cells increasing until they occupy 90% of each cell
-cells do not grow anymore in size above the zone of elongation

19. The Zone of Maturation
-the cells that elongated in the zone of elongation are differentiated into specific cell types
-many epidermal cells develop roots hairs, increasing surface area to absorb nutrients and water
-the ground meristem produces parenchyma cells, they are found in the interior of the epidermis
        -this layer called the cortex can by many cell layers thick and it functions in storage
-the endodermis has walls filled with suberin, suberin is produced in bands called Casparian strips
-the stele is everything inside of the endodermis
-the primary xylem conducts water

20. Modified Roots
-most plants either produce tap roots or fibrous roots, however there are plants with roots specific to the function needed for that plant
-a root that comes from something other than a root is called a adventitious root
        

21. Stem Structure: External Form
-the shoot apical meristem produces stem tissue that creates bulges (primordia) these bulges will form into leaves, shoots, and flowers
-a node is the area where the leaf is attached
-the area between two nodes is called an internode
-the bud that is a product of the primary shoot apical meristem is called the axillary bud
-a leaf scar is from the leaves falling off the trees in the fall, a bundle scar is where the vascular connections were

24. Internal Form
-from the apical meristem  three primary meristems develop; the protoderm,the ground meristem, and the procambium 
-cells of the vascular cambium divide indefinitely and create a secondary tissue

25. Leaf External Structure
- two morphological groups- 
microphyll- one gapless vein, and
megaphylls- several veins
- leaves have evolved to have a 
flattened blade and slender stalk
- mutant leaves have been found
to never flatten

26. Leaf Blades - compound leaves= divided into leaflets
 - simple leaves= undivided
- compound leaves= divided into leaflets
    - pinnate= lined leaflets
    - palmate= radial leaflets
- alternate leaves have 
one bud per leaf
- compound leaves have two leaves per bud

28. Leaf Internal Structure
- entire surface covered with transparent epidermis and cuticle, lower epidermis contains stomata and guard cells
- two layers of tissue ( the palisade and spongy mesophyll) rest between the upper and lower epidermis 
- veins, stomata, and intercellular spaces function together for gas exchange

29. THANK YOU!