1. Plant Structure

2. “Plants have to be exquisite to survive because they can’t run.” Plasticity- ability to mold form to microenvironment Morphology adapted to environment

3. Roots Anchors plant, stores nutrients, absorbs minerals and water Taproot system (lateral roots) – Dicots and Gymnosperms – Stores nutrients Fibrous root system – Many small roots grow from stem – shallow – monocots

4. Root modifications Root hairs- extensions of root epidermal cells, increase surface area Prop roots Storage roots Strangling aerial roots

5. Pneumatophores- air roots

6. Stems Alternating nodes and internodes – Nodes=leaf attachment – Internodes=stem between nodes Axillary bud- tissue between leaf and stem that can turn into a new shoot, most are dominant Terminal bud (apical bud)- developing leaves, top of plant

8. Apical dominance Terminal bud inhibits axillary buds How is elongation an evolutionary advantage? Once terminal bud is gone, axillary buds break dormancy, and grow into shoots with their own terminal bud

9. Modified stems Stolons-strawberry runners Rhizomes-horizontal stems Tubers-enlarged rhizomes, eyes=axillary buds

10. Leaves Photosynthetic organ Stomata facilitate gas Exchange Surface area – Water loss – Light collection

11. Modified Leaves Tendrils Spines Storage leaves Reproductive leaves

12. Plant Cells Plant cells differentiate in embryo and at meristems Primary and secondary cell wall, central vacuole, Chloroplasts Three types of Plant cell

13. Parenchyma cells Thin, flexible primary cell walls, no secondary cell wall Large central vacuole Photosynthetic cells in leaves Soft parts of plant

14. Collenchyma cells Thick primary cell walls Used for support (celery strings) Flexible- support without inhibiting growth

15. Sclerenchyma cells Thick Secondary Cell Wall Reinforced with lignin Can’t grow, only occur in parts of the plant that are done growing Seed coating, nut shells, pear crunchies

17. Water conducting Xylem cells Elongated, dead at functional maturity – Less resistance – More volume Water moves from roots to leaves Pits allow water to move laterally

18. Sugar conducting phloem Alive at functional maturity Lack organelles or Nucleus  companion cell controls function in phloem Sugar flows from source to sink

19. Meristems generate cells for new organs Indeterminate growth- plant grows throughout life Determinate growth- period of no growth, set final size Meristem- undifferentiated cells, can grow into any type of cell

20. Meristems Apical- tips of roots and stems (buds), allow plant to grow longer (primary growth) Lateral meristems- surround stem and roots, allow plant to grow in girth (secondary growth)

21. Primary and secondary growth happen each year, in different areas of the plant Primary growth lengthens branches and roots Secondary growth thickens and strengthens previous years growth

22. Primary growth Roots – Root cap protects meristem – Produces all three tissues – Zone of division – Zone of elongation – Zone of maturation

23. Primary growth of stems Axillary meristem Apical meristem Leaf primordia Apical meristem suppresses lateral growth Axillary buds develop from leftover meristem Elongation of shoot comes from growth of internode cells

24. Secondary Growth Occurs in stems and roots, not in leaves Vascular cambium – Produces xylem and phloem – Last year’s phloem becomes this year’s inner bark Cork cambium – Produces cork (outer bark) – Waterproofed w/ suberin

25. ???

26. Maple syrup overview Sugar storage (seasonal) Phloem – Source  sink Pressure/suction – Respiration – Osmosis 40:1  sap: syrup ratio

27. What factors will affect sap production?