1. Chapter 5 Notes – Pages 90 - 107 1 White Oak, Illinois State Tree White oak trees have bark that is off-whitish to ashy gray in color. It can be very scaly and platelike. Older trees often have patches of nearly smooth bark. Rounded lobes & Acorns

2. Read Page 90 2

3. Today, we are going to learn about Plant Body Structure Plant Life Spans Ground Tissue System Vascular System Tissues Dermal Tissue System Plant Growth Primary & Secondary growth 3

4. Plant Body Structure All plants have the same basic body plan Plant body is organized into 2 Systems Root System (underground portion) Tap Root Branch Roots Shoot System (aerial portion) Stem Leaves Flowers & Fruits *only in flowering plants* 4

5. Plant Organs Roots Stems Leaves Flower Parts Fruits 5

6. Figure 5-1 6 Branch roots Developing fruit Nodes (areas of leaf and axillary bud attachment) Axillary bud Flower Internode (area between adjacent nodes) Shoot system Root system Rosette of basal leaves Petiole Blade Leaf Stem Taproot Fig. 5-1, p. 92

7. Plants grow below & above ground Plants need resources from both environments Below ground Dark Moist Nutrients / Dissolved minerals Roots anchor the plant to the ground Absorbs Water Above ground Sunlight Carbon Dioxide 7

8. 2 Different types of Plant Body Herbaceous Plants Do not develop persistent woody parts above ground Typically green exterior Die after growing season Woody Plants Develop persistent woody parts above ground Persist after growing season 8

9. Plant Life Spans Annuals Herbaceous plants that grow, reproduce, & die in 1 year or season Examples: Corn, sunflowers, most food garden plants Biennials Herbaceous plants that take 2 years to complete their life cycles Examples: Carrots, cabbage, celery, & parsley Perennials Woody or herbaceous plants that live for more than 2 years Aerial shoots of herbaceous perennials die each winter Grow back in Spring Examples: All trees, rhubarb, onions, asparagus, iris 9

10. Cells & Tissues of the Plant Body The cell is the basic structural and functional unit of plants Plant cells are organized into tissues Tissues are groups of cells that form a structural and functional unit Simple tissues – 1 kind of cell Complex tissues – 2 or more kinds of cells 10

11. 3 Plant Tissue Systems Tissues are organized into 3 tissue systems 1. Ground Tissue System Most of the plant body Functions include photosynthesis, storage, structural support 2. Vascular tissue system (think of veins) The plumbing system of the plant Extends throughout the plant body Conducts water, dissolved minerals, and food (dissolved sugar) 3. Dermal Tissue System Strengthens & Supports the plant This system covers the plant body (like skin) 11

12. Tissue Systems throughout the plant 12

13. 1. Ground System Tissue Composed of 3 Simple Tissues 1. Parenchyma Cells have thin primary cell walls Unspecialized – Can differentiate into other kinds of cells Functions: Photosynthesis, storage, & secretion Most common type of cell & tissue in plants 2. Collenchyma Cells have unevenly thickened primary cell walls 3. Sclerenchyma “Sclero” means “Hard” Cells have both primary cell walls & thick secondary walls Provides support to plant body 13

14. Parenchyma Cells 14 Thin Primary Cell Walls

15. Collenchyma Cells 15 Thick Cell Walls

16. Sclerenchyma Cells 16 Have both primary and secondary cell walls

17. 2. Vascular Tissue System Composed of 2 Complex Tissues Xylem Conducts water and dissolved minerals Transfers from Roots  stem & leaves Composed of 2 types of cells Tracheids – chief water conducting cells Vessel Elements – have holes in end cell walls Phloem Conducts food throughout the body Composed of 4 types of cells Sieve-tube elements – highly specialized cells Companion cells Phloem fibers (long tapered cells) Phloem parenchyma cells 17

18. 3. Dermal Tissue Systems Composed of 2 Complex Tissues Epidermis Periderm 18

19. Epidermis Outermost layer of herbaceous plant, usually one cell thick Covers the primary plant body (leaves, young stems and roots) Prevent Water Loss Secretes a waxy cuticle Stomata regulates gas exchange using guard cells Composed of 2 types of cells Guard cells Trichomes 19

20. Stomata 20

21. Periderm Replaces epidermis in woody plants Forms the protective, outer bark Outermost layer of cells covering a woody stem or root 21

22. Periderm 22 Geranium Cortex (interior of stem) Exterior environment Remnants of epidermis Cork cells Cork cambium Periderm Cork parenchyma Fig. 5-10, p. 103

23. Table 5-2a, p. 104

24. Table 5-2b, p. 104

25. Primary Growth Increase in stem and root length Result of activity of apical meristems at the tips of roots and at the buds of stems Apical Meristem An area of cell division at the tip of a stem or root in a plant; produces primary tissues Bud A dormant embryonic shoot that eventually develops into an apical meristem

26. Root Tip

27. Stem Tip

28. Secondary Growth Increase in stem and root girth Secondary growth is localized, typically as long cylinders of active growth throughout the lengths of older stems and roots Lateral Meristem An area of cell division on the side of a vascular plant Gives rise to secondary tissues 2 Lateral Meristems Vascular Cambium Cork Cambium

29. Lateral Meristems and Secondary Growth