In the absence of transpiration water moves up xylem because of
1. root pressure
2. turgor pressure
4. high soil mineral concentration
High root pressure can cause water to be lost by leaves through the process of
Ringing experiments prove all but
1. Food is translocated through phoem
2. Water is translocated through xylem
3. Leaves are the sinks of phloem transport
4. The phloem tissue can be regenerated if the cambium is intact.
Loss of solutes from a cell leads to
1. Increase in water potential
2. Decrease in solute potential
3. Increase in pressure potential
4. All of the above
Apparently _______________ is the source of energy for keeping stomata open.
3. ion transfer
4. sodium pump
Maintaining turgor pressure in guard cells requires an uptake of
About _______________ % of the water taken in by roots is lost by transpiration.
Essential ions except _______________ are
removed from the roots and relocated through the xylem.
1. movement of soluble organic materials through plants.
2. movement of water through the apoplast.
3. evidence of root pressure.
4. negative pressure created by transpiration.
Stomata close when the guard cells:
1. lose water.
2. photosynthesis begins and the internal CO2 concentration decreases.
3. gain chloride ions.
4. become turgid.