1. Plant Structure Willow shoot

2. Monocot vs. Dicot Woody/herbaceousHerbaceous; never woody 75% of all angiosperms22% of all angiosperms -true of only flowering plants -Eudicots: group of plants share a common pollen structure diff. from mono. and di.

4. Monocot ExamplesDicot Examples Palm Trees  no wood  overlapping leaf bases Corn Peanut: not a nut  legume! Tomato

5. Monocot Seed Comes to Life! Seed coat – From the wall of the embryo sack (mother tissue) Endosperm – Food supply containing 3 sets of chromosomes (2 from the mother and 1 from the father) Embryo – Immature plant Cotyledon – Seed leaf Plumule – Shoot Radicle – Root

6. Dicot Seed Comes to Life! Seed coat – From embryo sack wall and endosperm tissue (During development, the endosperm stops dividing and is absorbed into the embryonic tissues.) Embryo – Immature plant Cotyledon – Food storing seed leaf Plumule – Shoot Hypocotyl – Stem Radicle – Root

7. Plant Parts

8. Meristems – forever young tissues; divide actively throughout plant’s life –These cells divide to generate additional cells: Initials- generative cells that remain in the meristem. Derivatives- Those that are displaced from the meristem and continue to divide for some time until the cells they produce begin to specialize within developing tissues. –New cells created via mitosis and derivative cells pushed further and further away from initials Plant Growth & Development

9. Apical meristems : located at the tips of roots and in the buds of shoots –supply cells for the plant to grow in length. –Primary growth initial root and shoot growth produced by apical meristem elongation occurs restricted to youngest parts of the plant (ex: tips of roots & shoots) Locations of Meristematic Tissues

10. –Secondary growth: thickening of roots and shoots. Produced by lateral meristems Develop in slightly older regions of roots and shoots (ex: vascular and cork cambium) Lateral meristems: allow the plant to increase in girth (circumference) Locations of Meristematic Tissues

11. Meristems

12. Building a House 1.Foundation is laid 2.Construction of the frame 3.Installation of plumbing, heating, etc 4.Waterproof walls and roof 5.Food stored in appropriate places Building a plant 1.Meristems give rise to all tissues 2.Three tissue systems give rise to the major organs of a plant 3.Installation of the vascular tissue (plumbing) 4.Installation of dermal tissues –covering, skin 5.Installation of ground tissue –parenchyma

13. Types of Roots Taproot –Primary root –Able to grow deep Water absorption –Ex: dandelion, carrots Fibrous Root –No root grows larger than another –Prevents erosion –Ex: grasses, peas

14. Root Cap: covers root tip & protects the meristem as the root pushes through the abrasive soil during primary growth. –The cap also secretes a lubricating slime. Growth in length is concentrated near the root ’ s tip, where three zones of cells at successive stages of primary growth are located. –zone of cell division –zone of elongation –zone of maturation Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Primary Growth in Roots

16. Vascular Plant Organs are Composed of 3 Tissue Systems: (outer protective covering) (everything else; energy transformation, storage & support)

18. Dicot RootMonocot Root

19. Plant Shoot

20. Primary Growth of the Shoot

21. Stem Anatomy

22. Monocot StemDicot Stem

23. Anatomy of a Tree Trunk After several years of secondary growth, several zones are visible in a stem.

24. Leaf Anatomy

25. Typical Dicot Leaf X-Section Palisade Parenchyma Spongy Parenchyma Vascular bundles Epidermis Cuticle Stoma Guard Cells

26. Typical Monocot Leaf X-Section Xylem Phloem Bulliform Cells Stoma Epidermis Midvein Vein Bundle sheath cell

27. Leaf Stomata: Allow Gas Exchange Guard cells Stoma

28. Plant Cell Structure cell wall chloroplastchloroplast nucleusnucleus central vacuole

29. Cell Wall Structure middle lamella primary cell wall secondary cell wall membranes that contain chloroplasts

30. Cell Wall Structure plasmodesmataplasmodesmata Microscopic channels in cell wall Allow for transport (proteins; used in phloem cells)

31. Plant Cell Types Xylem Tracheids Vessel elements Phloem Sieve-tube members Companion cell Xylem Tracheids Vessel elements Phloem Sieve-tube members Companion cell

32. Vascular tissue: runs continuous throughout the plant transports materials between roots and shoots. –Xylem transports water and dissolved minerals upward from roots into the shoots. (water the xylem) –Phloem transports food from the leaves to the roots and to non-photosynthetic parts of the shoot system. (feed the phloem) Vascular Tissue

33. The water conducting elements of xylem are the tracheids and vessel elements. Xylem

34. XylemXylem TracheidsTracheids –Characteristics tapered elongated cellstapered elongated cells connect to each other through pitsconnect to each other through pits secondary cell walls strengthened with ligninsecondary cell walls strengthened with lignin –Functions transport of water plus dissolved mineralstransport of water plus dissolved minerals supportsupport

35. Xylem Vessel ElementsVessel Elements –Characteristics shorter and wider than tracheidsshorter and wider than tracheids possess thinner cell walls than tracheidspossess thinner cell walls than tracheids Aligned end-to-end to form long micropipesAligned end-to-end to form long micropipes dead at functional maturitydead at functional maturity –Functions transport of water plus dissolved mineralstransport of water plus dissolved minerals supportsupport

36. Water conducting cells of the xylem

37. Food and minerals move through tubes formed by chains of cells, sieve-tube members. –sieve plates –companion cell Phloem

38. PhloemPhloem Sieve-tube MembersSieve-tube Members –Characteristics living cells arranged end-to-end to form food- conducting cells of the phloemliving cells arranged end-to-end to form food- conducting cells of the phloem lack lignin in their cell wallslack lignin in their cell walls mature cells lack nuclei and other cellular organellesmature cells lack nuclei and other cellular organelles alive at functional maturityalive at functional maturity –Functions transport products of photosynthesistransport products of photosynthesis

39. PhloemPhloem Companion CellsCompanion Cells –Characteristics living cells adjacent to sieve-tube membersliving cells adjacent to sieve-tube members connected to sieve-tube members via plasmodesmataconnected to sieve-tube members via plasmodesmata –Functions support sieve-tube memberssupport sieve-tube members may assist in sugar loading into sieve-tube membersmay assist in sugar loading into sieve-tube members Companion CellsCompanion Cells –Characteristics living cells adjacent to sieve-tube membersliving cells adjacent to sieve-tube members connected to sieve-tube members via plasmodesmataconnected to sieve-tube members via plasmodesmata –Functions support sieve-tube memberssupport sieve-tube members may assist in sugar loading into sieve-tube membersmay assist in sugar loading into sieve-tube members

40. Food conducting cells of the phloem

41. Ground tissue fills the interior of the plant. It contains three basic cell types: –Parenchyma cells –Collenchyma cells –Sclerenchyma cells Ground Tissue Dermal tissue Vascular tissue Ground tissue

42. Parenchyma CharacteristicsCharacteristics –least specialized cell type –only thin primary cell wall is present –possess large central vacuole –generally alive at functional maturity FunctionsFunctions –make up most of the ground tissues of the plant –storage –photosynthesis –can help repair and replace damaged organs by proliferation and specialization into other cells CharacteristicsCharacteristics –least specialized cell type –only thin primary cell wall is present –possess large central vacuole –generally alive at functional maturity FunctionsFunctions –make up most of the ground tissues of the plant –storage –photosynthesis –can help repair and replace damaged organs by proliferation and specialization into other cells

43. Parenchyma

44. CollenchymaCollenchyma CharacteristicsCharacteristics –possess thicker primary cell walls the that of parenchyma –no secondary cell wall present –generally alive at functional maturity FunctionsFunctions –provide support without restraining growth CharacteristicsCharacteristics –possess thicker primary cell walls the that of parenchyma –no secondary cell wall present –generally alive at functional maturity FunctionsFunctions –provide support without restraining growth

45. Collenchyma

46. SclerenchymaSclerenchyma CharacteristicsCharacteristics –have secondary cell walls strengthened by lignin –often are dead at functional maturity –two forms: fibers and sclereids FunctionsFunctions –rigid cells providing support and strength to tissues CharacteristicsCharacteristics –have secondary cell walls strengthened by lignin –often are dead at functional maturity –two forms: fibers and sclereids FunctionsFunctions –rigid cells providing support and strength to tissues

47. Two other sclerenchyma cells, fibers and sclereids, are specialized entirely in support. –Fibers are long, slender and tapered, and usually occur in groups. Those from hemp fibers are used for making rope and those from flax for weaving into linen. –Sclereids, shorter than fibers and irregular in shape, impart the hardness to nutshells and seed coats and the gritty texture to pear fruits.

48. Fiber Cells

49. Sclereids