why protect a dying leaf?. 42.1 - how are plant bodies organized; how do they grow? p. 860 42.2 -...

Why Protect A Dying Leaf?

• 42.1 - How Are Plant Bodies Organized; How Do They Grow? p. 860

• 42.2 - The Tissues and Cell Types of Plants? p. 862

• 42.3 - The Structures, Functions of Leaves, Roots, & Stems? p. 865

• 42.4 - How Do Plants Acquire Mineral Nutrients? p. 873

• 42.5 - How Do Plants Move Water Upward from Roots to Leaves? p. 876

Chapter #42 – Plant Anatomy & Nutrient

Transport7th Edition in Audesirk, Audesirk, and Byers

Chapter #24 – Plant Anatomy & Nutrient Transport

The Art and Science of

LivingSurvive (live)

Reproduce

Support the bodyObtain water & nutrientsTransport water & nutrientsObtain energyGrow and DevelopExchange gases?Protection from Herbivory

Angiosperms (Monocots and

Dicots)

• Flowering plants (called Angiosperms) are divided into two groups (monocots and dicots) based on the structure of their flowers, leaves, vascular tissue, roots, and seeds.

A. Largest phylum of living plants.B. 250,000 + species.C. Seeds enclosed by fruits.

Plant AnatomyRoots & Shoots• Root and shoot

systems are made up of basic plant organs: roots, leaves, stems, flowers.

Root System

Functions• Anchor plant.• Absorb water

and minerals.• Store sugar as

starch.• Transport

materials• Produce some

hormones.• Interact with

soil microbes.

• Photosynthesis (primarily in leaves)

• Transport of materials (water, minerals, sugars, and hormones among leaves, flowers, fruits, and roots)

• Reproduction• Hormone synthesis

Shoot System

Functions

Angiosperms (Monocots and

Dicots)

• Monocots have one cotyledon (seed leaf)– e.g. grasses, lilies, palms, orchids

• Dicots have two cotyledons (seed leaves)– e.g. deciduous trees (drop leaves

in winter), bushes, many garden flowers

Structure is used in classification

Monocots: flower parts in

3’s Dicots: flower parts in 4’s, 5’s,

6’s

Flowers

Monocots: parallel veins in leaves

Dicots: network of veins in the

leaves

Leaves

Monocots: small vascular bundles

scattered throughout the

stem.

Dicots: large vascular bundles

arranged in a ring around the

stem.

Stems

Monocots: fibrous root

system with no main tap root.

Dicots: Main tap root, with smaller

side roots branching off.

Roots

Monocots: single cotyledon;

endosperm and cotyledon are

separate.

Dicots: two cotyledons;

endosperm is contained in the

cotyledon.

Seeds

Plant Tissues

Dermal Tissue- Epidermis- Periderm

Ground Tissue- Parenchyma- Collenchyma- Sclerenchyma

Vascular Tissue- Xylem- Phloem

• Covers flowers, seeds, fruit.

• Secretes a waxy substance called cuticle (cuticular membrane - hydrophobic) as waterproofing.

• May produce special structures such as hairs (root hairs). Why?

Dermal Tissue:

Epidermis

Dermal Tissue:

Periderm• Replaces epidermis on roots and stems of woody plants with age.

• Composed mainly of thick, waterproof cork cells.

• Protects stems and roots.

• Anchor system (doesn’t absorb water & minerals).

Plant Tissues

Parenchyma

Collenchyma

Sclerenchyma

• Non-dermal, non-vascular.

• Thin-walled cells• Alive at maturity• Many functions,

including photosynthesis, starch storage, hormone production.

Ground Tissue:

Parenchyma

• Flexible support tissue.

• Elongated cells with irregular shapes and unevenly thickened walls.

• Living at maturity.

Ground Tissue:

Collenchyma

• Support tissue.• Elongated cells

with thick cell walls.

• Dead at maturity.

• Forms long fibers, or smaller sclerids (such as stone cells in pears).

Ground Tissue:

Sclerenchyma

• Sclerenchyma fibers

• Long, tube-like cells, joined end-to-end, that transport water and minerals from soil to leaves.

• Two types of cells: tracheids (in conifers) and vessel elements (in flowering plants).

Vascular Tissue: Xylem

• Tissue that transports dissolved sugars (sap) in a plant.

• Two types of cells:• Sieve tubes

(alive but no nucleus)

• Companion cells

Vascular Tissue: Phloem

In Review. . . .

Monocots

In Review. . . .

Dicots

Why Protect A Dying Leaf?