Plant Anatomy and Physiology

    I. How do plants survive on land?
        A. The green algae evolution connection.
        B. Life on land, exposed to air and soil instead of water environment.
        C. How is this possible?

    II. Key definitions
        A. Plant anatomy
        B. Plant morphology
        C. Plant physiology

    III. Plant anatomy
        A. Tissues
        B. Four plant tissue systems:
            1. Dermal tissue (epidermis)
            2. Vascular tissue
                a) Xylem = conducts water and dissolved minerals (there are xylem vessels and xylem tracheids).
                b) Phloem = conducts dissolved sugars from the leaves to other regions of the plant.  Phloem is composed of sieve elements (sieve
                    tube members + companion cells)
            3. Ground tissue: parenchyma, collenchyma, and sclerenchyma (two types: sclereids and fibers)
            4. Meristem: apical, lateral, and intercalary meristems and axillary buds. All are sites of cell division in plants.
                a) Development vs. Growth

    IV. Plant morphology
        A. Plant organs: roots, stems, and leaves.
        B. Root functions
        C. Root tissue structure: epidermis, cortex (ground tissue), vascular, and meristem.
        D. Plant shoot: stems and leaves.
            1. Stem functions
            2. Stems consist of nodes and internodes.
            3. Stem tissue structure: epidermis, cortex (ground tissue), pith (ground tissue), and vascular tissue.
            4. What do leaves do?
            5. Leaf structure:
                a) Epidermis has stomata (singular, stoma) = small pores surrounded by guard cells.
                    (1) Guard cells = control the opening of the stomatal pore. Allows CO2 to enter and O2 and evaporated H2O to exit.
                    (2) Transpiration = evaporative loss of water through the stomata.
                b) Ground tissue is called mesophyll tissue.  Two types: palisade mesophyll and spongy mesophyll.
                c) Vascular tissue (leaf ‘veins’)
                    (1) Bundle sheath cells = fiber cells that surround the vein, giving it strength.

    V. Plant physiology
        A. Water transport pathway: water is needed in the leaves but available only in the soil!
            1. The role of root hairs and the epidermis.
            2. Casparian strip in the endodermis (the innermost layer of the cortex) regulates what gets in.
            3. Water moves to the xylem, up to the leaves and if not needed, evaporates from the leaf.
        B. How does water move up a plant?
            1. It moves by the same mechanism that we use to suck water up a straw!   Cohesion, Adhesion, and Hydrogen bonding all play a role in
                this process.
        C. Water can move at a rate of 2 feet/minute in most plants.
        D. Dissolved sugar transport
            1. Dissolved sugar solution moves from the leaf to other parts of the plant by a water pressure driven process.
            2. Moves at a rate of approximately 2 inches/minute.