Assertion: Water and minerals cannot cross the endodermis and enter the vascular cylinder via the apoplast.
Reason: Casparian strip is the barrier located in transverse and radial walls of each endodermal cell and is made of lignin.
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: 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.
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: 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.
What do A, B, C and D represent in the following figure?
A | B | C | D | |
1. | carrier protein | symport | uniport | antiport |
2. | carrier protein | uniport | antiport | symport |
3. | carrier protein | antiport | symport | uniport |
4. | carrier protein | uniport | symport | antiport |
Assertion: The concentration of free sugar in the sink is always lower than in the sieve tube.
Reason: The unloaded sugar is consumed during growth or metabolism or converted to insoluble polymers such as starch.
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.
Diffusion:
I. does not require any energy expenditure
II. is dependent on a living system
III. is a fast process
IV. is the only means for gaseous movements in plants
1. Only I and IV are correct
2. Only I, II and IV are correct
3. Only I, III and IV are correct
4. Only II and III are correct
Substances that have a hydrophilic moiety:
1. have to be transported across the plasma membrane by active transport
2. can diffuse across the plasma membrane at a slower rate, if larger in size
3. do not need a concentration gradient to diffuse across the plasma membrane
4. need to be facilitated even along the concentration gradient
Facilitated diffusion allows cells to:
1. achieve uphill transport without ATP energy
2. select substances for uptake
3. stop transport of hydrophilic substances
4. decrease the rate of diffusion of lipophilic substances
Unlike a symporter and an antiporter, a uniporter:
1. is not an integral membrane protein
2. is a cell surface carbohydrate
3. is not a co-transporter
4. cannot be used for active transport