Presentation on theme: "1. Review How are tissues distributed in plant roots 2. Apply Concepts Why is it important that the root endodermis permits only a one way passage of materials."— Presentation transcript:
1. Review How are tissues distributed in plant roots 2. Apply Concepts Why is it important that the root endodermis permits only a one way passage of materials 3. Classify Draw and label a diagram to show how roots absorb water and nutrients- also include a brief description
CH 23 PLANT STRUCTURE AND FUNCTION 23.2 Roots
Types of Root Systems Taproot systems Fibrous root systems.
Taproot Systems Taproot Long and thick primary root Smaller branch roots Mainly found in dicots.
Fibrous Root System Many equally sized branch roots that grow separately from the base of the stem Begins with one primary root Help hold topsoil in place Found mainly in moncots.
Dermal Tissue Also called Epidermis Protection Absorption Root hairs to increase surface area.
Ground Tissue Cortex is one portion of ground tissue Directly inside of epidermis Water and minerals move through to get to center of root Store photosynthesis products (starch).
Ground Tissue Endodermis Completely encloses the vascular cylinder Plays essential role in moving water and minerals to the center of root.
Vascular Tissue Vascular cylinder Region made up of Xylem and Phloem.
Apical Meristem Root cap Protects meristem Secrets slippery substance to help root move through soil Cells constantly being scraped away and replaced.
Root Functions Uptake nutrients Transport nutrients Support plant Anchor in ground Store nutrients.
Uptake Nutrients Need inorganic nutrients Also trace minerals.
Transport Nutrients Active transport brings mineral ions across the epidermis High mineral ions concentration causes water molecules to move into the plant by osmosis.
Transport Nutrients Water and dissolved minerals pass through the cortex and move toward the vascular cylinder.
Transport Nutrients Vascular cylinder is enclosed by the endodermis and a special waterproof zone called a Casparian strip.
Casparian Strip Forces water and minerals through the cell membranes of the endodermis rather than in between the cells Controls water and minerals entering vascular cylinder doesn’t allow to leak back out.
Root Pressure Water is forced in by osmosis due to active transport of minerals Water enters through casparian strip and is forced up.
Root Pressure Glass tube replaced stem and leaves of carrot.