Roots Stems and Leaves Roots Stems and Leaves

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Roots, Stems, and Leaves

Roots, Stems, and Leaves

Roots, Stems, and Leaves Three of the principal organs of seed plants are roots,

Roots, Stems, and Leaves Three of the principal organs of seed plants are roots, stems, and leaves. Together these plant organs function in: 1. Transport 2. Protection 3. Coordination of plant activities

Plant Tissue Systems Each part of a plant consists of 3 types of tissue:

Plant Tissue Systems Each part of a plant consists of 3 types of tissue: 1. Dermal tissue 2. Vascular tissue 3. Ground tissue

Dermal Tissue • The “skin” of a plant contains a “waxy” layer called a

Dermal Tissue • The “skin” of a plant contains a “waxy” layer called a cuticle • Functions to prevent water loss

Vascular Tissue • Plants “bloodstream” • Transports water and nutrients throughout the plant. •

Vascular Tissue • Plants “bloodstream” • Transports water and nutrients throughout the plant. • Made of Xylem and Phloem

Xylem • Water moving tissue • The xylem is part of the vascular system

Xylem • Water moving tissue • The xylem is part of the vascular system of a plant. Similar to veins and arteries in animals. • It also provides stability to the plant through turgor pressure. • Damage to the xylem would effect how well the plant could move water throughout its tissue and it may not be able to support the weight of the leaves and branches (with decreased pressure).

Phloem • Food transport tissue. • Transports solutions of nutrients and carbohydrates • Damage

Phloem • Food transport tissue. • Transports solutions of nutrients and carbohydrates • Damage to the phloem can decrease or stop the flow of nutrients throughout the plant and cause all or part of the plant to die.

Nutrient Transport through Phloem • Using the Phloem, many plants pump sugars out of

Nutrient Transport through Phloem • Using the Phloem, many plants pump sugars out of the leaves and roots and into their fruit.

Ground Tissue • Cells that lie between dermal and vascular tissue • Made of

Ground Tissue • Cells that lie between dermal and vascular tissue • Made of cells whose cell walls have different thicknesses

Meristematic Tissue • The only plant tissue that produces new cells by mitosis •

Meristematic Tissue • The only plant tissue that produces new cells by mitosis • Located at the tips of stems and roots • Apical Meristem increase plant length • Cells start out alike but then differentiate

Roots Two main types: 1. Taproots – The taproot and its lateral roots penetrate

Roots Two main types: 1. Taproots – The taproot and its lateral roots penetrate deeper into 2. the soil than fibrous roots. Found mainly in dicots. Fibrous roots usually do not penetrate the soil very deeply. Because their roots attach themselves firmly to soil particles, plants with fibrous root systems are especially useful in preventing soil erosion. Found mainly in monocots.

Root Structure and Growth • The root’s surface is covered with cellular projections called

Root Structure and Growth • The root’s surface is covered with cellular projections called root hairs. Root hairs provide a large surface area through which water and nutrients can enter the plant. Root hairs

Root Function • 1. Anchor a plant • 2. Absorb water • 3. Absorb

Root Function • 1. Anchor a plant • 2. Absorb water • 3. Absorb dissolved nutrients

Root Functions • Minerals enter the roots through active transport. • Water enters by

Root Functions • Minerals enter the roots through active transport. • Water enters by osmosis Root hairs Active transport of minerals Movement of water by osmosis

Examples of Root Vegetables Carrot Sweet Potato Radish Ginger Parsnip

Examples of Root Vegetables Carrot Sweet Potato Radish Ginger Parsnip

Stems- Functions • Produce leaves, branches and flowers • Hold leaves up in the

Stems- Functions • Produce leaves, branches and flowers • Hold leaves up in the sunlight • Transport various substances between roots and leaves

Examples of Stem Vegetables Asparagus Rhubarb Bamboo Celery

Examples of Stem Vegetables Asparagus Rhubarb Bamboo Celery

Leaves • The structure of a leaf is optimized for absorbing light and carrying

Leaves • The structure of a leaf is optimized for absorbing light and carrying out photosynthesis. • The leaves and stems together form shoots.

Example of Leaf Vegetables Lettuce Spinach Basil Brussel Sprouts Cabbage Broccoli

Example of Leaf Vegetables Lettuce Spinach Basil Brussel Sprouts Cabbage Broccoli

Why don’t Plants dry out in the sun? • Stomata are pore-like openings in

Why don’t Plants dry out in the sun? • Stomata are pore-like openings in the underside of the leaf that allow carbon dioxide and oxygen to diffuse into and out of the leaf. • Plants keep their stomata open just enough to allow photosynthesis to take place but not so much that they lose an excessive amount of water through transpiration. • Transpiration is the evaporation of water through plant leaves. • The stomata open and close in response to changes in water pressure within the guard cells. When there is enough water the stomata are open When it is dry, the stomata are closed.

Monocots vs Dicots

Monocots vs Dicots

Transport in Plants • Root pressure – the starting point for the movement of

Transport in Plants • Root pressure – the starting point for the movement of water through the vascular system of the plant. • Capillary Action – The tendency of water to rise in a thin tube. • Transpiration – loss of water through a plant’s leaves. • All work together to move water through xylem tissue of even the tallest plant.

Transport in Plants The ability of a liquid to flow in narrow spaces without

Transport in Plants The ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity. Paper towels absorb liquid through capillary action, allowing a fluid to be transferred from a surface to the towel. The small pores of a sponge act as small capillaries, causing it to absorb a comparatively large amount of fluid. Some modern sport and exercise fabrics use capillary action to "wick" sweat away from the skin. Video? Water Transport (3: 14)

BRAIN POP-Plant Growth (3: 20) Amoeba Sisters (8: 40) Amoeba Sisters

BRAIN POP-Plant Growth (3: 20) Amoeba Sisters (8: 40) Amoeba Sisters