Assertion: In most plants, root pressure is a minor mechanism driving the ascent of xylem sap.
Reason: For the most part, xylem sap is not pushed from below by root pressure but is pulled up.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: Adding solutes always lowers the water potential and the solute potential of a solution is always negative.
Reason: Solute potential is also called as the osmotic potential because solutes affect the direction of osmosis.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false

Assertion: Water transport across biological membranes is too specific and too rapid to be explained entirely by diffusion through the lipid layer.
Reason: Water molecules are so small that they move relatively freely across the lipid bilayer, even though the middle zone is hydrophobic.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Short distance lateral transport from root hair to vascular cylinder via symplast route requires repeated crossings of plasma membranes as the solutes exit one cell and enter the next.
Reason: The symplast pathway consists of cell walls and extracellular spaces.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Nutrients pass easily through the sieve tube members of Phloem.
Reason: Though alive, sieve tube members lack such organelles as the nucleus, ribosomes and a distinct vacuole.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: The cohesive force of water in tracheids and vessels is stronger than the pull of gravity.
Reason: The tensile strength of a column of water varies inversely with the diameter of the column.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Given equal cross sectional areas of xylem, a plant with larger-diameter vessels can move more water up its stems than a plant with narrower tracheids.
Reason: The volume of liquid moving in a column per second is inversely proportional to ${\mathrm{r}}^4$ where r is the radius of the column, at constant pressure.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

What do A, B, C and D represent in the following figure?
 

Potometer works on the principle of
1. Potential difference between the tip of the tube and that of the plant
2. Amount of water absorbed equals the amount transpired
3. Osmotic pressure
4. Root pressure

The translocation of organic solutes in sieve tube members is supported by
1. Root pressure and transpiration pull
2. P-proteins
3. Mass flow involving a carrier and ATP
4. Cytoplasmic streaming