Active transport of substances does not involve:
1. transport of solute along the concentration gradient.
2. use of a specific membrane transport protein.
3. hydrolysis of ATP.
4. transport of solute against a concentration gradient.

The direction of water movement in plants can always be predicted by measuring:
1. pressure potential
2. number of aquaporins
3. proton gradients
4. water potential (ψ)

Give ${\mathrm{\psi }}_{\mathrm{P}}$ = 0.25 MPa and ${\mathrm{\psi }}_{\mathrm{S}}$ = -0.50 MPa,what will be the resulting Ψ:
1. +0.75 MPa.
2. -0.75 MPa.
3. -0.25 MPa.
4. +0.25 MP

Identify the correct statements regarding bulk flow in plants:
I. Driven primarily by pressure potential.
II. More effective than diffusion over greater distances.
III. Depends on the difference in pressure potential at the source and sink.
IV. Depends on the force of gravity on a column of water.
V. May be due to either positive or negative pressure potential.
1. I, II and III only
2. II, III and V only
3. II, III, IV and V only
4. I, II, III and V only.

The Casparian strip in plant roots:
1. is located in the walls of the outermost portion of the cortex.
2. is composed predominantly of lignin and hence is impermeable to water.
3. ensures active uptake of all minerals by the roots.
4. ensures that all water and dissolved substances must pass through a cell membrane before entering the vascular cylinder.

Translocation in xylem will not be facilitated by:
1. The cohesion of water molecules.
2. A negative water potential.
3. The root parenchyma.
4. The active transport of solutes.

It is a common observation that pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected. The most probable cause for this would be:

The flow of water through the xylem is regulated by:
1. passive transport of mineral ions by the root endodermis.
2.the number of nuclei in the companion cells in the phloem.
3. the evaporation of water from the leaves.
4. active transport by tracheid and vessel elements.

Advantages of tracheids over vessels for long-distance transport to great heights include:
I. Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders.
II. The smaller the diameter of the xylem, the more likely cavitation will occur.
III. Cohesive forces are greater in narrow tubes than in wide tubes of the same height.
1. Only I and II
2. Only I and III
3. Only II and III
4. I, II and III

Substances travelling via the symplast move from cell-to-cell through:
1. membrane proteins.
2. phospholipid channels.
3. tonoplast.
4. plasmodesmata.