BIOL 260 Lecture Notes - Lecture 11: Phloem, Sucrose, Sieve Tube Element
Document Summary
Describe the pathways of water and nutrient transport through xylem, including the tissues and structures involved and the chemical/physical driving forces. Outline the experimental evidence in support of the cohesion-tension mechanism of plant transpiration. Discuss the pressure-flow model of sugar transport in phloem, including the tissues and structures involved and the chemical/physical driving forces. Pathways of water and nutrients transport through the xylem. Higher temperature gives the atmosphere a higher tendency to attract water. When it is windy, water evaporates faster, and the atmosphere takes up more water. The lower the humidity, the higher the transpiration (more water is lost at lower humidity) Plant cells do not need to expend any energy in moving water up the trunk. The water moves through the xylem, which is composed of dead cells. The atmosphere is what pulls the water to move up the trunk. Roots are the entry point of water and nutrients (3 different pathways in which water moves)
