Roots
ROOTS * is an organ of a plant that typically lies below the surface of the soil. * a part of a plant body that bears no leaves, and therefore also lacks of nodes. * is the beginning of the vascular system pipeline that moves water and minerals from the soil up to the leaves and fruits.
FUNCTIONS OF ROOTS: * Underground (usually) * Anchor the plant in the soil * Absorb water and nutrients * Conduct water and nutrients * Food Storage
ROOT SYSTEM: 1. Tap root system * A root system consisting of one prominent main root with smaller lateral roots branching from it. * Ex: carrots, beets, sugar beets, parsnips, turnips, rutabagas, radishes 2. Fibrous Root System * A root system consisting of several adventitious roots of approximately equal size that arise from the base of the stem. * These roots are adventitious which means they can grow from plant organs other than roots e.g. stems. * Ex: sweet potatoes, cassava
STRUCTURE OF ROOTS: 1. Epidermis – The outer layer of cells * Root Hair * An extension of an epidermal cell of a root that increases absorptive capacity of the root. * Absorptive unicellular extensions of epidermal cells of a root that functions as the major site of water and mineral uptake. * Increase surface area of root in contact with moist soil, increasing root’s absorptive capacity. 2. Cortex * Primary tissues of a root bound on the outside by the epidermis and on the inside by the endodermis. 3. Endodermis * a single layer of cells in a root that separates the cortex tissues from the pericycle. * Casparian Strip * A band of waterproof material around the radial and transverse cells of the endodermis * Ensures that water and minerals enter the xylem only by passing through the endodermal cells 4. Pericycle * a layer of cells immediately inside the endodermis. Branch roots arise from the pericycle. 5. Vascular
FUNCTIONS OF ROOTS: * Underground (usually) * Anchor the plant in the soil * Absorb water and nutrients * Conduct water and nutrients * Food Storage
ROOT SYSTEM: 1. Tap root system * A root system consisting of one prominent main root with smaller lateral roots branching from it. * Ex: carrots, beets, sugar beets, parsnips, turnips, rutabagas, radishes 2. Fibrous Root System * A root system consisting of several adventitious roots of approximately equal size that arise from the base of the stem. * These roots are adventitious which means they can grow from plant organs other than roots e.g. stems. * Ex: sweet potatoes, cassava
STRUCTURE OF ROOTS: 1. Epidermis – The outer layer of cells * Root Hair * An extension of an epidermal cell of a root that increases absorptive capacity of the root. * Absorptive unicellular extensions of epidermal cells of a root that functions as the major site of water and mineral uptake. * Increase surface area of root in contact with moist soil, increasing root’s absorptive capacity. 2. Cortex * Primary tissues of a root bound on the outside by the epidermis and on the inside by the endodermis. 3. Endodermis * a single layer of cells in a root that separates the cortex tissues from the pericycle. * Casparian Strip * A band of waterproof material around the radial and transverse cells of the endodermis * Ensures that water and minerals enter the xylem only by passing through the endodermal cells 4. Pericycle * a layer of cells immediately inside the endodermis. Branch roots arise from the pericycle. 5. Vascular