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.
The pathway of water from the soil through the plant to the atmosphere is best represented by which of the following sequences?
1. endodermis- cortex - epidermis - vessel elements - intercellular spaces in mesophyll - stomata.
2. epidermis - cortex - Casparian strip - endodermis - sieve cells - intercellular spaces in the mesophyll - stomata.
3. Casparian strip - root hairs - epidermis - cortex - xylem - endodermis - intercellular spaces in mesophyll - stomata.
4. root hairs - cortex - endodermis - vessel elements - intercellular spaces in mesophyll - stomata.
Which is an incorrect statement.
1. Translocation of minerals up the xylem is an active process
2. The target cells unload the minerals by an active process
3. The absorption of minerals by plants is mostly an active process
4. Minerals usually flow up the vessels along with the transpiration stream.