ch29_lecture

Plant Tissues : 

Plant Tissues Starr/Taggart’s Biology: The Unity and Diversity of Life, 9e Chapter 29

Slide 2: 

DMA What characteristics of angiosperms and gymnosperms allow them to be the dominant land plants?

Slide 3: 

AngiospermsThe Flowering Seed-Bearing Plants Flowers Coevolution with pollinators Insects Bats Birds Seed Ovary

Key Concepts: : 

Key Concepts: Angiosperms and gymnosperms dominate the plant kingdom These are seed-bearing vascular plants with complex above-ground structures and root systems These plants have three major categories of tissue systems: ground, vascular, and dermal

Slide 5: 

Fig. 29.2, p. 500 3 tissue systems Ground Bulk of plant Vascular Conducting tissues Distribute water and solutes Dermal Covers and protects Overview of the Plant Body

Basic Definitions: : 

Basic Definitions: Stem: region of the plant containing the following tissues: meristem, support, vascular, and buds (buds give rise to new stems, leaves, flowers) Leaf: a chlorophyll containing tissue that is the major region of photosynthesis Root: typically found below ground, responsible for: Water and nutrient absorption, anchoring the plant, food storage

Types of Plant Tissues-Simple : 

Types of Plant Tissues-Simple Parenchyma Storage Support Mesophyll Photosynthetic Collenchyma Flexible support for primary tissues Sclerenchyma Support Protects seeds Lignin impregnated Fibers Sclereids

Slide 8: 

Fig. 29.6, p. 502 Types of Plant Tissues-Simple

Complex Tissues : 

Complex Tissues Vascular Xylem Water Dissolved ions Mechanical support Phloem Conducts sugars and solutes Dermal Epidermis Cuticle Waxes Cutin Restriction of water loss Stem and leaf epidermis Guard cells Stoma Periderm

Dicots and MonocotsSame Tissues, Different Features : 

Dicots and MonocotsSame Tissues, Different Features Dicot Two cotyledons 4 - 5 floral parts or multiples Netlike array of leaf veins 3 pores in pollen grain Vascular bundles in a ring in stem Monocots One cotyledon 3 floral parts or multiples Parallel veins in leaves 1 pore in pollen grains Vascular bundles throughout ground tissue of stem

Slide 11: 

Fig. 29.10, p. 503 In seeds, two cotyledons (part of the embryo) Usually four or five floral parts (or multiples of these) Usually a netlike array of leaf veins Basically, three pores of furrows in pollen grain vascular bundle Vascular bundles arrayed as a ring in stem DICOTS MONOCOTS In seeds only one cotyledon Usually three floral parts (or multiples of three) Usually a parallel array of leaf veins Basically, one pore or furrow in pollen grain Vascular bundles distributed ground tissue of stem

Slide 12: 

Fig. 29.13a, p. 505 epidermis pith vascular bundle cortex Sieve-tube members and companion cells in phloem fibers in phloem vessels in xylem meristematic cell Ring of vascular bundles dividing ground tissue into cortex and pith Stem, transverse section; enlargement of a vascular bundle shown at right

Slide 13: 

Fig. 29.13b, p. 505 epidermis vascular bundle ground tissue vessel in xylem air space sheath of thick-walled Sclerenchyma cells around mature vascular bundle Sieve-tube member in phloem companion in phloem Vascular bundles distributed throughout ground tissue Stem, transverse section; enlargement of a vascular bundle shown at right

Meristems: Where Tissues Originate : 

Meristems: Where Tissues Originate Shoot Apical Meristem Lateral Meristem Root Apical Meristem

Primary Structure of Shoots : 

Primary Structure of Shoots Apical meristem: a mass of self-perpetuating cells responsible for primary growth at root and shoot tips Procambium: gives rise to vascular tissue Protoderm: gives rise to the epidermis Ground meristem: gives rise to the cortex or part of the ground tissue

Types of Stems : 

Types of Stems Stems can be either classified as part of monocots or dicots. Stems can also be classified as herbaceous or woody. Herbaceous: flexible, one season growth Woody: inflexible, multiple seasons of growth

Different Types of Leaves : 

Different Types of Leaves

Slide 18: 

Fig. 29.16, p. 507 UPPER EPIDERMIS PALISADE MESOPHYLL SPONGY MESOPHYLL LOWER EPIDERMIS cuticle-coated cell of lower epidermis one stoma (opening across the epidermis) cuticle of upper epidermis leaf vein (one vascular bundle inside the leaf) xylem phloem Water and dissolved mineral ions move from roots into stems, then into leaf vein (blue arrow) Products of Photosynthesis (pink arrow) enter vein and are transported to stems, roots) Oxygen and water vapor escape from the leaf through stomata Carbon dioxide from the surrounding air enters the leaf through stomata

The Fine Structure of Leaves : 

The Fine Structure of Leaves Cuticle covers epidermis Stomata Mesophyll (photosynthetic) Veins (vascular bundles)

Stomata : 

Stomata Stomata are leaf openings that are regulated by guard cells. Why are stomata typically found on the underside of leaves?

Root Systems : 

Root Systems Taproot Root System (most dicots) Primary root gives rise to lateral roots Youngest lateral roots closest to root tips Fibrous Root System (most moncots) Primary root short-lived Adventitous roots arise from stem, lateral roots branch from these

Slide 22: 

Fig. 29.17, p. 508

Structure of Roots : 

Structure of Roots Epidermis Cortex: ground tissue between epidermis and vascular bundles Vascular cylinder Endodermis: outside the cortex, inside the pericycle Pericycle: produces branch roots Phloem Xylem Pith: parenchyma tissue at center of root

Slide 24: 

Fig. 29.18, p. 508 VASCULAR CYLINDER: endodermis pericycle xylem phloem cortex epidermis fully grown root hair Vessels have now matured; root hairs and the vascular cylinder are about to form Cells elongate; sieve tubes of phloem form and mature; xylem’s vessel members start to form Most cells have stopped developing Cells are dividing rapidly at apical and primary meristems Quiescent center (no cell division) root cap 100 µm

Secondary GrowthThe Woody Plants : 

Secondary GrowthThe Woody Plants Annuals Non-woody One growing season Biennials Two growing seasons 1st: roots, stems, leaves 2nd: flowers, seeds, death Perennials Vegetative growth Seed formation Woody plants

Trunk of a Redwood : 

Trunk of a Redwood

Activity of the Vascular Cambium : 

Activity of the Vascular Cambium Vascular cambium is a lateral meristem Secondary xylem forms on the inner face Secondary phloem forms on the outer face

Secondary Growth in the Root : 

Secondary Growth in the Root Woody plant Vascular cambium forms secondary xylem and phloem

A Look at Wood and Bark : 

A Look at Wood and Bark

Early Wood, Late Wood, and Tree Rings : 

Early Wood, Late Wood, and Tree Rings Heartwood Center Xylem filled with metabolites Aromatic Sapwood Secondary growth between heartwood and vascular cambium Growth Rings Seasonal Hardwood (maple) and Softwood (pine)

Hardwood - Oak : 

Hardwood - Oak