5 Written questions
5 Matching questions
- What are nucleating sites and how are the reduced?
- What drives xylem water transport?
- Explain how water in soil depends on soil type and structure
- What are the 4 mechanisms and driving forces acting on water transport within the plant and between plant and the environment?
- Explain water transport against gradients in plants:
- a this includes things such as the particle diameter and the surface area per gram of soil, this affects the adhesion properties of water
- b 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.
- c 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)
- d this is driven by pressure gradients
- e transpirational water loss, xylem transport, water movement in soil and transport through layers of living cells
5 Multiple choice questions
- 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
- the ease at which the water moves through the soil (remember spaces between soil particles)
- in plants with very elastic cell walls there can be a change in water potential resulting in a large change in water volume, they can swell with increased water availability.
- molecular diffusion and bulk flow
5 True/False questions
What is an exodermis? → the formation of gas bubbles
In most plants as turgor pressure approaches zero what happens to the relative cell volume? → there is a negative hydrostatic pressure
What is field capacity? → the formation of gas bubbles
What influences and drives osmosis? → it is influenced by both diffusion and bulk flow and driven by water potential gradients. It occurs spontaneously with these forces.
What is surface tension? and why is this important in water? → it is the energy used to increase the surface area, the amount of surface area occupied by the interface of air and water. this is important because remember that water is more attracted to itself then to air molecules. (This is what can create contact angels) water generally wants to minimize the surface area at the air water interface