Secret Life of Plants

1. Secret Life of Plants Plant Anatomy

3. Terms • Node – place where leaf petiole attaches • Internode – stem between nodes • Terminal bud – at the end of a branch • Axillary bud – at the base of a leaf

4. Tap root – large central, vertical root • Lateral root – branches off the taproot • Fibrous roots – all roots about the same size, no central tap root

5. Root Diversity Prop Root – support tall, top heavy plants

6. Storage roots – store food and water

7. Pneumatophores – air roots, enable root system to obtain oxygen

8. Stem Diversity Bulbs – vertical, underground shoots consisting of enlarged bases of leaves that store food

9. Tuber Enlarged ends of rhizomes specialized for storing food Eyes – clusters of axillary buds

10. Rhizome Horizontal stem that grows below surface

11. Leaf Diversity Tendrils – modified leaves, used to cling to support Spines – leaves, but photosynthesis is carried out in green flesh Storage leaves – stores water Brachts – leaves that surround group of flowers, attracts pollinators Reproductive leaves – produce adventitious plantlets, fall off and take root in soil

12. Tissue Types • Dermal Tissue – outer protective covering • Epidermis – nonwoody plants • Periderm – woody plants • Ground Tissue – neither dermal nor vascular • Pith – internal to vascular tissue • Cortex – external to vascular tissue • Vascular Tissue – long distance transport of materials between roots and shoots • Xylem – water and minerals upward • Phloem – sugars downward

13. Xylem – Tracheids & Vessels Water transporting system

14. Phloem – Sieve tubes Sugar transporting system

15. Plant Growth • Primary Growth • Growth in length of roots or shoots • Growth at the apical meristem (tips of roots and shoots) • Secondary Growth (will do later) • Growth in diameter of stem or root • Growth at the vascular cambium • Growth at the cork cambium

16. Root Structure

18. Tissues in Dicot Root • Epidermis – no cuticle • Cortex – parenchyma, food storage • Endodermis – inner layer of cortex, sealed • Pericycle – outer rim of vasc. bundle, lateral roots • Phloem – sugar transport • Cambium – area of potential new xylem & phloem growth • Xylem – water & mineral transport

19. Lateral Root Growth

20. Dicot & Monocot Stem

21. Tissues in Dicot Stem • Epidermis • Cortex • Vascular Bundles Phloem Cambium Xylem • Pith ( more storage)

22. Tissues in Monocot Stem • Epidermis • Ground tissue • Scattered vascular bundles in the ground tissue • Only phloem and xylem, no cambium

23. Leaf Anatomy

24. Tissues in mesophytic leaf • Upper epidermis • Palisade mesophyll • Vein • Xylem • Phloem • Bundle sheath cells surround the X and P • Spongy mesophyll with air spaces • Lower epidermis

25. Epidermis details • Cuticle (Wax) layer on outside of epidermis • Ordinary Epidermal cells have no chloroplasts • Stoma – opening in the leaf for gas exchange • Guard cells (with chloroplasts) are on either side of the stoma • Usually more stoma on the bottom of the leaf

26. Mesophyll Region • Photosynthetic cells • Palisade cells maximize exposure to light • Spongy cells allow accumulation of gases • Veins • Xylem delivers water and minerals • Phloem transports photosynthetic products for metabolic needs of cells or storage • Bundle sheath cells surround vein & protect

27. Secondary Growth • Growth in Girth • Vascular cambium produces secondary xylem and phloem • Cork Cambium produces peridermand cork