第二十五章: 植物的組織 前言.

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1 第二十五章: 植物的組織 前言

2 Mount Saint Helens Eruption
Volcano is located in southwestern Washington state In 1980 it erupted, blowing 500 million metric tons of rock and ash outward Ash and lava devastated about 40,500 acres of what had been forest

3 Recovery Plants moved into the empty habitat almost immediately
Fireweed and blackberry were early colonists In less than ten years, willow and alders were on the scene

4 Success of the Angiosperms
The angiosperms are seed-bearing vascular plants In terms of distribution and diversity, they are the most successful plants on Earth The structure and function of this plant group help explain its success

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6 Plant Life Histories Annuals complete life cycle in one growing season
Biennials live for two seasons; flowers form in second season Perennials grow and produce seeds year after year

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9 植物的綜觀 枝梢(Shoots) 包括: 莖 葉 花(生殖枝) 根 (Roots)

10 蕃茄 典型的被子植物

11 三種植物的組織系統 基本組織系(Ground tissue system) 維管組織系(Vascular tissue system) 表層組織系(Dermal tissue system)

12 分生組織(Meristems): 組織起源的地方
在莖或根的頂尖上形成 初生分生組織: 既,表層分生組織, 基本分生組織,原始形成層等 次生生長組織: 圍環的增加 維管束形成層(Vascular cambium) 木栓形成層(Cork cambium),既皮層

13 Cutting Specimens radial transverse tangential

14 Meristems Regions where cell divisions produce plant growth
Apical meristems Lengthen stems and roots Responsible for primary growth Lateral meristems Increase width of stems Responsible for secondary growth

15 Apical Meristems Lengthen shoots and roots
Cells that form at apical meristems Protoderm Ground meristem Procambium activity at meristems new cells elongate and start to differentiate into primary tissues

16 Lateral Meristems Increases girth of older roots and stems
Cylindrical arrays of cells vascular cambium cork cambium thickening

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18 植物組織的型態 單純組織 複合組織

19 Made up of only one type of cell
Simple Tissues Made up of only one type of cell Parenchyma (薄璧組織) Collenchyma (厚角組織) Sclerenchyma (厚璧組織)

20 植物組織的型態

21 Parenchyma: A Simple Tissue 柔軟,濕潤之出生生長的 細胞;有分生能力
Comprises most of a plant’s soft primary growth Cells are pliable, thin walled, many sided Cells remain alive at maturity and retain capacity to divide Mesophyll is a type of parenchyma that contains chloroplasts

22 Collenchyma: A Simple Tissue
Specialized for support for primary tissues Cells are elongated, with walls (especially corners) thickened with pectin Makes stems strong but pliable Cells are alive at maturity

23 Collenchyma: A Simple Tissue
Supports mature plant parts Protects many seeds Cells have thick, lignified walls and are dead at maturity Two types: Fibers: Long, tapered cells Sclereids: Stubbier cells

24 厚角組織(Collenchyma): 提供出生組織的柔軟支撐, 具伸長形狀,有果膠質連接 的加厚細胞璧

25 厚璧組織(Sclerenchyma): 支撐成熟植物體, 保護種子, 有木質素, 厚璧組織由: 厚璧細胞(Sclereids)及 纖維(Fibers)組成

26 棉花種子的纖維 亞麻莖內的強壯纖維

27 維管束組織(Vascular tissue)
Complex Tissues 複合組織 維管束組織(Vascular tissue) 皮層組織(Dermal tissue) Composed of a mix of cell types Xylem Phloem Epidermis

28 Xylem Conducts water and dissolved minerals
Conducting cells are dead and hollow at maturity vessel member tracheids

29 Phloem: A Complex Vascular Tissue
sieve plate Transports sugars Main conducting cells are sieve-tube members Companion cells assist in the loading of sugars sieve-tube member companion cell

30 維管束組織(Vascular tissue):輸送
木質部(Xylem) 導管(Vessel members) 假導管(Tracheids) 韌皮部(Phloem) 篩管細胞(Sieve-tube members) 伴細胞(Companion cells)

31 木質部(Xylem) 韌皮部(Phloem) 導管(Vessel members) 假導管(Tracheids) 篩管細胞 伴細胞

32 Epidermis (皮層組織): A Complex Plant Tissue
Covers and protects plant surfaces Secretes a waxy, waterproof cuticle In plants with secondary growth, periderm replaces epidermis

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34 單子葉植物(Monocot)和雙子葉植物(Dicot) 相同組織，不相同的特徵
1 cotyledon 2 cotyledons 4 or 5 floral parts 3 floral parts Netlike veins Parallel veins 3 pores 1 pore Vascular bundles dispersed Vascular bundles in ring

35 枝梢的初生構造: 莖和葉如何形成與內部構造

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39 莖內部構造: Dicot

40 Dicot

41 Adapted for Photosynthesis
Leaves are usually thin High surface area-to-volume ratio Promotes diffusion of carbon dioxide in, oxygen out Leaves are arranged to capture sunlight Are held perpendicular to rays of sun Arrange so they don’t shade one another

42 細看葉子 葉子間的相似與相異處 葉子的細部構造 葉子的神奇用處與誤用

43 單葉 複葉

44 葉子的細部構造

45 Mesophyll: Photosynthetic Tissue
A type of parenchyma tissue Cells have chloroplasts Two layers in dicots Palisade mesophyll Spongy mesophyll

46 Leaf Veins: Vascular Bundles
Xylem and phloem; often strengthened with fibers In dicots, veins are netlike In monocots, they are parallel

47 葉子的神奇用處與誤用

48 初生根的構造 主根系和鬚根系 根的內部構造

49 主根系 (tap root system) 鬚根系 (Fibrous root system)

50 根的內部構造

51 Internal Structure of a Root
Outermost layer is epidermis Root cortex is beneath the epidermis Endodermis, then pericycle surround the vascular cylinder In some plants, there is a central pith

52 Function of Endodermis
Ring of cells surrounds vascular cylinder Cell walls are waterproof Water can only enter vascular cylinder by moving through endodermal cells Allows plant to control inward flow

53 毛莨(a Dicot) 中心柱

54 玉米(a Monocot) 中心柱

55 柳 樹 側 根 的 形 成 過 程

56 Root Hairs and Lateral Roots
Both increase the surface area of a root system Root hairs are tiny extensions of epidermal cells Lateral roots arise from the pericycle and must push through the cortex and epidermis to reach the soil new lateral root

57 積聚次生生長: 木本植物 一年生植物(Annuals) 多年生植物(Perennials)

58 Secondary Growth Occurs in all gymnosperms, some monocots, and many dicots A ring of vascular cambium produces secondary xylem and phloem Wood is the accumulation of these secondary tissues, especially xylem

59 胡桃的莖部剖面圖

60 Vascular Cambium Lateral meristem One or two cells thick
Divides in two directions Cells formed to the outside become secondary phloem Cells formed to the inside become secondary xylem

61 維管束植物形成層活動模式圖

62 Woody Stem periderm (consists of cork, cork cambium,
and secondary cortex) secondary phloem HEARTWOOD SAPWOOD BARK vascular cambium

63 木材的切片

64 Annual Rings Concentric rings of secondary xylem
Alternating bands of early and late wood Early wood Xylem cells with large diameter, thin walls Late wood Xylem cells with smaller diameter, thicker walls

65 Types of Wood Hardwood (oak, hickory) Softwood (pine, redwood)
Dicot wood Xylem composed of vessels, tracheids, and fibers Softwood (pine, redwood) Gymnosperm wood Xylem composed mostly of tracheids Grows more quickly

66 year 1 2 3 Fig , p. 433 Fig b, p. 433