BSCI 207 Study Guide - Midterm Guide: Einstein Ring, Xylem, Transpiration

• School: University of Maryland
• Department: Biological Sciences Program
• Course: BSCI 207
• Professor: Bretton Kent

Document Summary

Gas exchange and bulk flow in animals: mammals exhibit tidal ventilation of their lungs. Specifically, describe the components of this model and how they each contribute to the movement of water. Water moves through the xylem by tugging forces from above transpiration and very little from osmosis below (especially in tall plants) Bulk flow of water from the roots to leaves mediated by continuous water potential gradient. Transpiration = evaporation of water from cells within the leaves (pull water out of leaves) Cohesion = cohesion of water molecules in the xylem sap as a result of hydrogen bonding. Tension = tension on the xylem sap as a result of transpiration. Generally, the waxy cuticle on leaves and stems is (permeable/impermeable) to water. In the light, guard cells pump out protons to facilitate the entry of k+ and cl- Higher k+ and cl- concentrations in stroma give the cells a more (negative/positive)