1. Plant Structure and Growth

2.  Roots anchor the plant in the soil, absorb minerals and water, and store food  Monocots have a fibrous root consisting of a mat of thin roots that spread out below the soil surface  Dicots have a taproot consisting of one large, vertical root that produces many smaller lateral roots ◦ Often store food  Carrots, turnips, beats

4.  Increase the surface area of the root enormously  Extensions of individual epidermal cells on the root surface

5.  Roots that raise above ground from stems or leaves  Function as props that help support tall stems

6.  Shoots consist of stems and leaves  Stems are alternating systems of nodes, the points at which leaves are attached, and internodes, the stem segment between nodes  The angle formed by each leaf and the stem is an axillary bud that has the potential to form a vegetative branch ◦ Most young plants’ are dormant and growth is usually concentrated at the tip, called the terminal bud

8.  Phenomenon where axillary buds are put into a state of dormancy so that the terminal bud, or apical meristem receives all the nutrients  Increases the plant’s exposure to light  Under certain circumstances, it may be stopped and the axillary buds are allowed to grow ◦ If top is eaten by an animal

9.  Stolons: runners of strawberry plants, grow on the surface of the ground and enable a plant to colonize large areas asexually when the single parent plant fragments into many smaller offspring

10.  Rhizomes: ginger plants, are horizontal stems similar to stolons except that they grow underground

11.  Tubers: potatoes; swollen ends of rhizomes specialized for storing food  Bulbs: onions, vertical underground shoots consisting mostly of the swollen bases of leaves that store food

12.  Main photosynthetic organs of most plants  Generally consist of a flattened blade and a stalk called the petiole which joins the leaf to the node of the stem

13.  The dermal tissue, or epidermis, is generally a single layer of tightly packed cells that cover and protect all young parts of the plant ◦ Root hairs are extensions of this tissue ◦ Secretes a waxy coating called the cuticle that helps retain water  The vascular tissue, in involved in the transport of materials between roots and shoots ◦ Xylem and Phloem

14.  Tracheid and vessel elements are elongated cells that are dead at functional maturity, and found in xylem ◦ Their secondary walls are interrupted by pits, thinner regions where only primary walls are present  Sieve-tube members are alive at functional maturity, lack organelles ◦ Nonconducting companion cells are connected to the sieve tubes and serves that cell with nutrients and help load sugar into the tubes

15.  The tissue that is neither dermal nor vascular  In dicot stems, it is divided into pith, internal to the vascular tissue, and the cortex, external to the vascular tissue  Functions in photosynthesis, storage, and support

16.  Parenchyma  Collenchyma  Sclerenchyma

17.  Thin and flexible walls with a large central vacuole  Transport sap in phloem  Perform most of the metabolic functions, synthesize and store various organic products  Fleshy tissue of most fruit is composed of parenchyma  “Stem Cells” of the plants ◦ Least specialized, but can be turned into other cells  Can grow an entire plant from one parenchyma cell

18.  Unevenly thicker cell walls  Grouped in strands or cylinders and help support young parts of the plant shoot ◦ Strings of celery  Provide support without restraining growth ◦ Do not have lignin in cell wall to make it strong

19.  Thick cell walls, cannot grow, function as support elements  Functionally mature cells are dead ◦ Provide a skeleton that supports the plant  Vessel elements and tracheids are sclerenchyma cells  Fibers and sclerids function solely in support

20.  Primary growth: elongation of the plant, achieved by apical meristems  Secondary growth: progressive thickening of roots and shoots, achieved by lateral meristems ◦ Cork cambium replaces the epidermis with a secondary tissue, such as bark, that is thicker and tougher ◦ Vascular Cambium adds layers of vascular tissues  Wood is the secondary xylem that accumulates over the years