All the following regarding the cohesion-tension model are true except:
1. Water movement is driven by transpiration.
2. The water potential of atmospheric air is more positive than that for xylem.
3. Cohesion represents the tendency for water molecules to stick together by hydrogen bonds.
4. The physical forces in the capillary-sized xylem cells make it easier to overcome gravity.

The most important problem faced by most plants during flooding is:
1. inability to receive sunlight
2. leaching of nutrients
3. damage to the root system
4. oxygen deprivation

Normally, the fastest delivery of water and minerals to the leaves of a tree is most likely to happen on a:
1. cool, dry day
2. warm, dry day
3. warm, humid day
4. very hot, dry, windy day

Mangrove plants are able to survive in water logged regions as their pneumatophores have:
1. Stomata
2. Halophytes
3. Parenchyma
4. Lenticels

All the following will be a selective advantage in dry, hot conditions except:
1. CAM pathway
2. reduced leaves with stomata on the lower surface
3. a thick cuticle covering the fleshy leaves
4. mutant unable to produce ABA

For most plants, in late spring, phloem transports:
1. amino acids from the root source to the symbiotic fungal sink.
2. sugars from the leaf source to the apical meristem sink.
3. nucleic acids from the flower source to the root sink.
4. sugars from the stem source to the root sink.

Xylem transports air by:
1. the proton pump
2. active transport
3. chemiosmosis
4. air is not transported by xylem normally

Identify the incorrect statement regarding xylem:
1. Xylem tracheids and vessels perform their vital function only after their death.
2. Tracheids have a strong cell wall deposited with cellulose fibrils forming thickened rings or spirals.
3. Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules.
4. Mass flow translocation between the source and the sink occurs due to a turgor pressure gradient.

The normal functioning of which of the following would be least dependent on active transport:

Which of the following is not required for transpiration?
1. adhesion of water molecules to cellulose.
2. cohesion between water molecules.
3. evaporation of water molecules.
4. active transport through xylem cells.