Water potential (Ψ) in plants is affected by:
I. mechanical pressure.
II. matrix effects (e.g., fluid cohesion and surface tension).
III. dissolved solutes.
IV. osmosis.
1. I, II and III only
2. I, III and IV only
3. II, III and IV only
4. I, II, III and IV

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

The water potential [Ψ] in root tissue was found to be -0.13 MPa. The Ψ of 0.1 M solution of sucrose is -0.23. If the root tissue is placed in this solution, the net water movement is expected to be
1. from the root tissue into the sucrose solution.
2. from the sucrose solution into the root tissue.
3. equal in both direction.
4. requiring ATP hydrolysis for either direction.

A cell has less number of aquaporins when compared to another cell in a plant. With respect to the latter cell, the former cell will have:
1. a faster rate of osmosis.
2. a lower water potential.
3. a higher water potential.
4. a lower rate of osmosis.

The presence of which of the following in a plant cell will be an argument against consideration of the entire plant as a single unit rather than a composite of many individual cells?
1. cell wall
2. cell membrane
3. plasmodesmata
4. tonoplast

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.

Water potential is best defined as the:
1. product of turgor pressure and pressure potential
2. difference between pressure potential and osmotic potential
3. combination of pressure potential and solute potential
4. difference between pressure potential and osmotic potential

Xylem in plants does not:
1. conduct material upward from the roots.
2. conduct materials within the dead cells.
3. transport large amounts of sugars and amino acids.
4. have a lower water potential than soil does.

Surface area for water absorption from soil by the roots of the plants is increased due to all of the following except:
1. root hairs
2. endodermis
3. mycorrhizae
4. fibrous arrangement of the roots

How many of the following processes involve active transport across membranes in plants?
I. the movement of mineral nutrients from the apoplast to the symplast.
II. the movement of sugar from mesophyll cells into sieve-tube members in maize.
III. the movement of sugar from one sieve-tube member to the next.
IV. K⁺ uptake by guard cells during stomatal opening.
V. the movement of mineral nutrients into cells of the root cortex.
1. 2
2. 3
3. 4
4. 5