← Water Test
5 Written Questions
5 Matching Questions
- What is water potential?
- What properties of water generates the physical forces to pull water up through the plant?
- How is apoplast movement regulated?
- What is field capacity?
- a the measurement of free energy of water per unit of volume. (J/m^3)
- b 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
- c the moisture holding capacity of a soil
- d water molecule attraction to a solid such as a cell wall or a glass tube
- e surfaces tension and adhesion at the evaporative surfaces of leaves
5 Multiple Choice Questions
- apoplast, symplast and transmembrane
- surface tension, adhesion and cohesion. the capillarity of a liquid
- adhesion and surface tension of water (more negative with increase curvature)
- 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.
- into the cell walls of the mesophyll where water vapor diffuses through leaf air spaces through the stomatal pore and across the boundary layer
5 True/False Questions
What two driving forces drive the direction and rate of water potential gradients? → the concentration of the solute and the pressure gradient
In most plants as turgor pressure approaches zero what happens to the relative cell volume? → there is a negative hydrostatic pressure
Within the plant cells what affects tugor? → 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)
What kind of pressure is between the xylem and cells? → into the cell walls of the mesophyll where water vapor diffuses through leaf air spaces through the stomatal pore and across the boundary layer
What is transpiration? → It is the formation of vapor/ gas bubble in flowing water which can rapidly collapse and produce shock waves provding energy to nucleating sites within the xylem.