plant structure and function ch 35 n.
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Plant Structure and Function Ch. 35 PowerPoint Presentation
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Plant Structure and Function Ch. 35

Plant Structure and Function Ch. 35

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Plant Structure and Function Ch. 35

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  1. Plant Structure and FunctionCh. 35

  2. Morphology of a Flowering Plant • Root system and shoot system are connected by vascular tissue that is continuous throughout plant

  3. Monocots vs. Dicots


  5. Nucleus Chloroplast Cell Wall Plant Cell

  6. Roots • Functions • Anchor plant in the soil • Absorb water and minerals • Store food

  7. Root Structure

  8. Root Systems Taproot Fibrous root

  9. • Red mangrove growing in seawater • Adventitious prop roots support and securely anchor this shrub in the mud and loose sand of tidal waters. • Close-up view of prop roots • Numerous pores called lenticels which provide gas exchange and an additional source of oxygen for the submersed roots.

  10. Epidermis Cortex Vascular cylinder -xylem -phloem Developing lateral root

  11. Modified Roots Storage roots. Prop root Buttress roots. Aerial roots

  12. Stems • Functions • Support • Transport • Storage

  13. Monocot arrangement

  14. Dicot arrangement

  15. Proximity of terminal bud inhibits growth of axillary buds (Apical dominance)

  16. Modified Stems Stolons—allow asexual reproduction Bulbs—store food Tubers—store food Rhizomes—horizontal stem

  17. Leaves • Leaf structure • Shape • Size • Edges

  18. Leaf Structure Mesophyll

  19. Stomata

  20. Modified Leaves • Tendrils—allow plant to cling to support • Spines—reduces water loss

  21. Modified Leaves • Storage—modified for water storage (succulents) • Bracts—attracts pollinators

  22. Modified Leaves • Reproductive leaves—produce adventitious plantlets which fall off and take root

  23. Tissue Systems 1. Ground System • Parenchyma • Collenchyma • Sclerenchyma --cube-shaped, thin and flexible cell walls --function in photosynthesizing and storing organic products and wound healing --elongated, thicker cell walls --cells grouped in strands or cylinders to support leaves and stems (parts that are still growing) --cells have rigid, thick walls with lignin --at maturity, consists of dead cells --supports and strengthens plant

  24. Tissue Systems -Conducts water and minerals from roots to plant -composed of dead cells that form water-pipe system Xylem -Conducts food throughout plant -composed of living cells arranged into tubules Phloem 2. Vascular System

  25. Water-conducting Cells of Xylem

  26. Sugar-conducting Cells of Phloem

  27. Sheath of sclerenchyma phloem xylem parenchyma

  28. Tissue Systems 3. Dermal Tissue System - Forms the outer covering of plants • Epidermis-outer layer of cells • covered by waxy cuticle • Stomata-structures that regulate • passage of gases into/out of plant

  29. Meristems: Primary Growth Growing region where cells actively divide Apical meristems- grow in length at tips of stems and roots

  30. Lateral meristems • Add thickness to woody plants, a process called secondary growth • Two lateral meristems • vascular cambium adds layers of vascular tissue called secondary xylem (wood) and secondary phloem • cork cambium replaces the epidermis with periderm, which is thicker and tougher

  31. Primary Growth in Roots

  32. Primary Growth in Shoots

  33. Secondary growth occurs in stems and roots of woody plants but rarely in leaves • Vascular cambium • Produces secondary xylem and phloem • Cork cambium • Produces tough, thick covering for stems and roots • Replaces epidermis

  34. Anatomy of a Tree Trunk • As a tree or woody shrub ages, the older layers of secondary xylem, the heartwood, no longer transport water and minerals • The outer layers, known as sapwood, still transport materials through the xylem

  35. Growth, morphogenesis, and differentiation produce the plant body • The three developmental processes of growth, morphogenesis, and cellular differentiation act in concert to transform the fertilized egg into a plant

  36. Growth: Cell Division and Cell Expansion • By increasing cell number, cell division in meristems increases the potential for growth • Cell expansion accounts for the actual increase in plant size

  37. The Plane and Symmetry of Cell Division • The plane (direction) and symmetry of cell division are immensely important in determining plant form • If the planes of division are parallel to the plane of the first division, a single file of cells is produced

  38. The Plane and Symmetry of Cell Division • If the planes of division vary randomly, asymmetrical cell division occurs

  39. The Plane and Symmetry of Cell Division • The plane in which a cell divides is determined during late interphase • Microtubules become concentrated into a ring called the preprophase band

  40. Genetic Control of Flowering • Flower formation involves a phase change from vegetative growth to reproductive growth • It is triggered by a combination of environmental cues and internal signals • Transition from vegetative growth to flowering is associated with the switching-on of floral meristem identity genes

  41. Plant biologists have identified several organ identity genes that regulate the development of floral pattern

  42. The ABC model of flower formation identifies how floral organ identity genes direct the formation of the four types of floral organs