1. Absorption from the Soil:
* Root Hairs: These tiny extensions of root epidermal cells increase the surface area for absorption of water and dissolved minerals from the soil.
* Osmosis: Water moves passively from the soil (high water potential) into the root cells (lower water potential) through osmosis. This movement is driven by the difference in water concentration between the soil and the root cells.
* Active Transport: Minerals are often present in lower concentrations in the soil than inside the root cells. Plants use energy (ATP) to move these minerals against their concentration gradient, actively transporting them into the root cells.
2. The Vascular System:
* Xylem: This network of dead, hollow tubes transports water and dissolved minerals upward from the roots to the rest of the plant.
* Transpiration Pull: Evaporation of water from the leaves creates a negative pressure (tension) that pulls water upwards through the xylem, like a straw.
* Cohesion-Adhesion: Water molecules stick together (cohesion) and also adhere to the walls of the xylem vessels, further aiding in the upward movement of water.
3. Delivery to Individual Cells:
* Phloem: This tissue transports sugars produced during photosynthesis throughout the plant, but it doesn't directly deliver water and minerals.
* Cell Walls: Water and minerals move from the xylem into the surrounding cells by diffusion and osmosis.
* Cell Membranes: These selectively permeable membranes regulate the passage of water and minerals into individual cells.
Here's a simplified breakdown:
1. Roots absorb water and minerals from the soil.
2. Water travels upwards through the xylem due to transpiration pull.
3. Minerals are actively transported into the xylem along with water.
4. Xylem delivers water and minerals to all parts of the plant, including leaves, stems, and flowers.
5. Individual cells take up water and minerals from the xylem.
Important Note: The vascular system (xylem and phloem) is crucial for large plants to transport water and nutrients effectively over long distances. This allows them to grow tall and access resources beyond their immediate surroundings.
