5 Written questions
5 Matching questions
- What can reduce tensile strength in a water column?
- Cohesion gives water a high what? Which is what?
- What is solute potential and what does it do?
- What drives transpirational water loss?
- a it is the effect of dissolved solutes on water potential. The solutes reduce free energy of water therefore increases disorder (independent of specific nature of solute)
- b transfer of water traveling between cell walls and any extra cellular spaces that have water in it on it's way to the root cortex driven by hydrostatic pressure
- c tensile strength. this is the maximum force per area that a continuous column of water can stand before breaking
- d this is driven by a gradient in water vapor concentration
- e gas bubbles
5 Multiple choice questions
- solute concentration, pressure and gravity
- the cohesion and adhesion properties of water make the liquid to vapor activation high in water, within the xylem the energy is not available to under go the change
- the random collisions and exchange of kinetic energy between water molecules driving a movement down concentration gradients
- via casparin cells in the endodermis, they contain radial cell walls composed of suberin (waxy substance) acting as a barrier to water making it cross the cell membrane
- type of median, the begging state of the cell (flaccid or turgid), and the pressure
5 True/False questions
Explain how water in soil depends on soil type and structure → There are no metabolic pumps to drive water, it only occurs when water is coupled with ion (solutes) to carry it. This can occur because the loss of the free energy by the solute is greater then the gain of free E of the water. (negative net change in E is produced)
What are the 4 mechanisms and driving forces acting on water transport within the plant and between plant and the environment? → transpirational water loss, xylem transport, water movement in soil and transport through layers of living cells
What is water potential? → the measurement of free energy of water per unit of volume. (J/m^3)
What are nucleating sites and how are the reduced? → they are sites that could provide the action energy required for water to undergo change for liquid to gas. This can occur due to gas bubbles and is avoided in the xylem via piths in water transfer which are to small for most bubbles to pass.
Water is pulled through the xylem via what kind of pressure? → into the cell walls of the mesophyll where water vapor diffuses through leaf air spaces through the stomatal pore and across the boundary layer