BIOA02H3 Lecture Notes - Pressure Gradient, Phloem, Semipermeable Membrane
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BIOA02H3 Full Course Notes
Verified Note
43 documents
Document Summary
From tree to seed: transport in plants, plant nutrition and soils, plant defense, plant life on the edge. Basic plant needs: sugar=carbon dioxide + light +water, water, oxygen, minerals: water transport through xylem, hypotheses on mechanisms of water transport. Answer: 3 hypotheses: capillary action, root osmotic push, transpiration. 1] capillary action- travels 1 m up xylem water move upward xylem through adhesion (water & tube walls) and cohesion (water & water molecutes). Capillary action is not strong enough for trees because it travels for 1 meter: root osmotic push- travels 3 m up xylem. Osmosis (osmotic pressure) is where water diffusion through semipermeable membrane such as the cell wall from a low concentration to a high concentration until both concentration are equal. Plant actively pump ions into root cells with atp . water moves into cells by osmosis when oot hair have greater osmotic pressure (high ion_ than surrounding soil.
