Chapter 27 Plant Tissues Cengage Learning 2016 27

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Chapter 27 Plant Tissues © Cengage Learning 2016

Chapter 27 Plant Tissues © Cengage Learning 2016

27. 1 Carbon Sequestration • Humans release CO 2 into the atmosphere by burning

27. 1 Carbon Sequestration • Humans release CO 2 into the atmosphere by burning fossil fuels and other plantderived materials • The amount of CO 2 in the atmosphere is increasing exponentially • Carbon offsets aim to reduce the amount of CO 2 in the atmosphere • Plants absorb CO 2 from the air and sequester it in their tissues via photosynthesis © Cengage Learning 2016

Carbon Sequestration • Carbon locked in giant sequoia trees can stay out of the

Carbon Sequestration • Carbon locked in giant sequoia trees can stay out of the atmosphere for centuries © Cengage Learning 2016

shoot tip (terminal bud) lateral bud flower node dermal tissue leaf fruit stem vascular

shoot tip (terminal bud) lateral bud flower node dermal tissue leaf fruit stem vascular tissues SHOOTS ROOTS ground tissue primary root lateral root hairs root tip root cap © Cengage Learning 2016 © 2016 Cenage Learning

The Plant Body • Most plants consist of roots and shoots – Roots are

The Plant Body • Most plants consist of roots and shoots – Roots are belowground plant parts • Absorb water and dissolved minerals • Store food • Support the plant – Shoots are aboveground plant parts • Stems provide structural support • Leaves are specialized for photosynthesis • Flowers are specialized for reproduction © Cengage Learning 2016

The Plant Body • All plant parts consist of the same tissues – Ground

The Plant Body • All plant parts consist of the same tissues – Ground tissues: make up most of a plant – Vascular tissues: distribute water and nutrients – Dermal tissues: cover and protect plant surfaces © Cengage Learning 2016 vascular tissues ground tissues dermal tissue

Monocots and Eudicots • Differences – Tissue organization – Number of cotyledons (seed leaves)

Monocots and Eudicots • Differences – Tissue organization – Number of cotyledons (seed leaves) • Monocots have one • Eudicots have two • Examples of monocots – Lilies, orchids, grasses, palms • Examples of eudicots – Shrubs and trees, vines, tomatoes, dandelions © Cengage Learning 2016

Monocots and Eudicots © Cengage Learning 2016

Monocots and Eudicots © Cengage Learning 2016

Monocots and Eudicots © Cengage Learning 2016

Monocots and Eudicots © Cengage Learning 2016

27. 3 Plant Tissues • Simple plant tissues – Consist of one cell type

27. 3 Plant Tissues • Simple plant tissues – Consist of one cell type – Parenchyma, collenchyma, sclerenchyma • Complex plant tissues – Consist of two or more cell types – Dermal and vascular tissues © Cengage Learning 2016

Simple Tissues • Parenchyma tissue – Comprised of parenchyma cells – Photosynthesis, storage, secretion,

Simple Tissues • Parenchyma tissue – Comprised of parenchyma cells – Photosynthesis, storage, secretion, tissue repair • Collenchyma tissue – Comprised of collenchyma cells – Pliable structural support • Sclerenchyma tissue – Comprised of fibers or sclereids – Structural support © Cengage Learning 2016

Complex Dermal Tissues • Epidermis – Comprised of epidermal cells and their secretions –

Complex Dermal Tissues • Epidermis – Comprised of epidermal cells and their secretions – Secretion of cuticle, protection, control of gas exchange and water loss • Periderm – Cork cambium, cork cells, and parenchyma cells – Protective cover on older stems, roots © Cengage Learning 2016

Complex Vascular Tissues • Xylem – Water-conducting tubes – Comprised of tracheids, vessel elements,

Complex Vascular Tissues • Xylem – Water-conducting tubes – Comprised of tracheids, vessel elements, parenchyma cells, sclerenchyma cells • Phloem – Sugar-conducting tubes – Comprised of sieve elements, parenchyma cells, sclerenchyma cells © Cengage Learning 2016

Plant Tissues © Cengage Learning 2016

Plant Tissues © Cengage Learning 2016

Vascular tissues one cell’s wall pit in wall parenchyma vessel of xylem © Cengage

Vascular tissues one cell’s wall pit in wall parenchyma vessel of xylem © Cengage Learning 2016 sieve plate of sievetube cell companion cell phloem fibers of sclerenchyma

27. 4 Stems • Provide support and position leaves for photosynthesis • Typically have

27. 4 Stems • Provide support and position leaves for photosynthesis • Typically have nodes, which give rise to new shoots or roots • Xylem and phloem are organized as vascular bundles – Arrangement differs between monocots and eudicots © Cengage Learning 2016

Monocot Stem epidermis fibers (sclerenchyma) epidermis vascular bundle phloem vessel tracheid parenchyma A A

Monocot Stem epidermis fibers (sclerenchyma) epidermis vascular bundle phloem vessel tracheid parenchyma A A cross-section of a corn stem shows how the vascular bundles in monocot stems are dispersed throughout the ground tissue. (A) left, © Cengage Learning; middle, Dr. Keith Wheeler/Science Source; right, © Herve Conge/© ISM/ Phototake; ht, © ISM/Phototake. © Cengage Learning 2016 xylem

Eudicot Stem epidermis vascular bundle pith cortex fibers (sclerenchyma) phloem tracheid vessel B A

Eudicot Stem epidermis vascular bundle pith cortex fibers (sclerenchyma) phloem tracheid vessel B A cross-section of a buttercup stem shows how all of the vascular bundles in a typical eudicot stem are arranged in a characteristic ring. This ring divides the stem’s ground tissue into regions of cortex and pith. In buttercup and many other plants, the stem becomes hollow with age as cells in its center die. (B) left, © Cengage Learning; middle and right, © ISM/Phototake. © Cengage Learning 2016 parenchyma xylem

27. 5 Leaves • Specialized for photosynthesis and gas exchange • Vary in size,

27. 5 Leaves • Specialized for photosynthesis and gas exchange • Vary in size, shape, surface specializations, and internal structure © Cengage Learning 2016

elliptic palmate acuminate odd pinnate © Cengage Learning 2016 lobed odd bipinnate pinnatisect elliptic

elliptic palmate acuminate odd pinnate © Cengage Learning 2016 lobed odd bipinnate pinnatisect elliptic odd pinnate

stem lateral bud blade node petiole sheath blade node © Cengage Learning 2016

stem lateral bud blade node petiole sheath blade node © Cengage Learning 2016

Leaf Anatomy • Mesophyll – Photosynthetic parenchyma with air spaces – Composes bulk of

Leaf Anatomy • Mesophyll – Photosynthetic parenchyma with air spaces – Composes bulk of the leaf • Leaf veins – Vascular bundles of leaves • Epidermis – Outermost tissue of a leaf, one cell thick – Outgrowths can form hairs, scales, spikes, etc. – Secrete waxy cuticle that slows water loss © Cengage Learning 2016

27. 6 Roots • Take up water and mineral ions from the soil •

27. 6 Roots • Take up water and mineral ions from the soil • Anchor a plant • Sometimes used for storage © Cengage Learning 2016

Fibrous Root System (Monocots) • Adventitious and lateral roots • Vascular cylinder divides cortex

Fibrous Root System (Monocots) • Adventitious and lateral roots • Vascular cylinder divides cortex and pith © Cengage Learning 2016

Taproot System (Eudicots) • Primary root and lateral branches • Central vascular cylinder ©

Taproot System (Eudicots) • Primary root and lateral branches • Central vascular cylinder © Cengage Learning 2016

Root Anatomy • Vascular cylinder (stele) – Column of vascular tissue – Runs lengthwise

Root Anatomy • Vascular cylinder (stele) – Column of vascular tissue – Runs lengthwise through center of root • Endodermis – Outer boundary of vascular cylinder – Help control which solutes are taken into plant’s vascular system • Pericycle – Layer of cells just inside root endodermis – Can give rise to lateral roots © Cengage Learning 2016

Monocot Root Anatomy © Cengage Learning 2016

Monocot Root Anatomy © Cengage Learning 2016

Eudicot Root Anatomy © Cengage Learning 2016

Eudicot Root Anatomy © Cengage Learning 2016

27. 7 Primary Growth • Lengthening of plant roots and shoots • Production of

27. 7 Primary Growth • Lengthening of plant roots and shoots • Production of leaves • Originates in apical meristems (regions of undifferentiated cells) © Cengage Learning 2016

Primary Growth in Shoots apical meristem in terminal bud immature leaf protoderm procambium ground

Primary Growth in Shoots apical meristem in terminal bud immature leaf protoderm procambium ground meristem hair apical meristem in lateral (axillary) bud procambium ground tissue M. I. Walker/Science Source © Cengage Learning 2016

protodermal tissue procambium Cell Enlargement vascular tissue ground meristem Cell Differetiationn apical meristem in

protodermal tissue procambium Cell Enlargement vascular tissue ground meristem Cell Differetiationn apical meristem in root tip procambium root cap ground meristem Cell Division protoderm apical meristem root cap A A longitudinal cut through the center of a root tip of onion (Allium), a monocot. Labels indicate where procambium is giving rise to the vascular cylinder; protoderm, to the epidermis; ground meristem, to the root cortex. B Dividing cells of root apical meristem give rise to protoderm, ground meristem, and procambium, which differentiate into dermal tissue, ground tissue, and vascular tissue. Regions of cell division, differentiation, and enlargement are indicated. (A) © Ed Reschke/Photolibrary/Getty Images; (B) © Cengage Learning; (in text) Michael Clayton/University of Wisconsin, Department of Botany. © Cengage Learning 2016

27. 8 Secondary Growth • Thickening of shoots and roots • Production of wood

27. 8 Secondary Growth • Thickening of shoots and roots • Production of wood • Two types of lateral meristems: – Vascular cambium – Cork cambium © Cengage Learning 2016

Chapter 28 Plant Nutrition and Transport © Cengage Learning 2016

Chapter 28 Plant Nutrition and Transport © Cengage Learning 2016

28. 2 Plant Nutrients and Availability in Soil • Nutrients – Elements or molecules

28. 2 Plant Nutrients and Availability in Soil • Nutrients – Elements or molecules essential for growth • Plants require sixteen nutrients – Nine macronutrients, required in large amounts – Seven micronutrients, required in trace amounts © Cengage Learning 2016

Macronutrients © Cengage Learning 2016

Macronutrients © Cengage Learning 2016

Micronutrients © Cengage Learning 2016

Micronutrients © Cengage Learning 2016

Properties of Soil • Soil consists of: – Mineral particles – Decomposing organic material

Properties of Soil • Soil consists of: – Mineral particles – Decomposing organic material (humus) – Water and air in spaces between particles • Mineral particles differ in size: – Sand (about 1 mm in diameter) – Silt (hundreds to thousands times smaller than sand) – Clay (even smaller than silt) © Cengage Learning 2016

28. 3 Root Adaptations for Nutrient Uptake • Osmosis drives water movement into roots

28. 3 Root Adaptations for Nutrient Uptake • Osmosis drives water movement into roots • Direction of water movement – From soil, through root’s epidermis and cortex, to xylem in vascular cylinder • Endodermis – Secrete waxy substance that forms Casparian strip • Transport proteins – Control the types and amounts of ions that move from soil water into plant body © Cengage Learning 2016

Root Uptake of Soil Water © Cengage Learning 2016

Root Uptake of Soil Water © Cengage Learning 2016

28. 4 Water Movement Inside Plants • Water that enters a plant travels lengthwise

28. 4 Water Movement Inside Plants • Water that enters a plant travels lengthwise through xylem tubes • Water flows laterally, from one tube to another, through pitted walls © Cengage Learning 2016

Cohesion-Tension Theory • Transpiration – Water evaporates from aboveground plant parts – Creates tension

Cohesion-Tension Theory • Transpiration – Water evaporates from aboveground plant parts – Creates tension on columns of water • Water has cohesion due to hydrogen bonds • Tension extends from leaves to roots © Cengage Learning 2016

Cohesion-Tension Theory Transpiration through open stomata creates negative pressure (tension) © Cengage Learning 2016

Cohesion-Tension Theory Transpiration through open stomata creates negative pressure (tension) © Cengage Learning 2016

Cohesion-Tension Theory Water molecules are connected by hydrogen bonds (cohesion) © Cengage Learning 2016

Cohesion-Tension Theory Water molecules are connected by hydrogen bonds (cohesion) © Cengage Learning 2016

Cohesion-Tension Theory Tension extends from leaves to roots, where water is taken up ©

Cohesion-Tension Theory Tension extends from leaves to roots, where water is taken up © Cengage Learning 2016

Stomata • When guard cells swell with water, stomata open • When guard cells

Stomata • When guard cells swell with water, stomata open • When guard cells lose water, stomata close • Water vapor diffuses out of a stoma when it is open © Cengage Learning 2016

Stomata Open © Cengage Learning 2016 Closed

Stomata Open © Cengage Learning 2016 Closed

28. 6 Movement of Organic Compounds in Plants • Conducting tubes of phloem are

28. 6 Movement of Organic Compounds in Plants • Conducting tubes of phloem are called sieve tubes • Each sieve tube consists of a stack of sieve elements • Each sieve element has an associated companion cell © Cengage Learning 2016

Sieve Elements • Sieve elements do not have pitted walls, so fluid only flows

Sieve Elements • Sieve elements do not have pitted walls, so fluid only flows through their ends • Sieve plates separate individual sieve elements © Cengage Learning 2016

Pressure Flow Theory • Pressure flow theory – Osmotic pressure pushes sugar-rich fluid inside

Pressure Flow Theory • Pressure flow theory – Osmotic pressure pushes sugar-rich fluid inside a sieve tube from source to sink. • Source – Where sugars are produced or released from storage • Sink – Where sugars are being used © Cengage Learning 2016