The pressure-flow hypothesis explains the translocation of sugars in the phloem. Which of the following statements regarding this hypothesis is INCORRECT?
Active loading of sugars at the source creates a high solute concentration in the sieve tubes.
Water moves from the xylem to the phloem at the source, increasing turgor pressure.
Sugars are unloaded at the sink, lowering the solute concentration and water potential.
Water moves from the sink to the source via the phloem, driven by a pressure gradient.
Related Questions
The bulk movement of substances through the vascular tissue is called:
Diffusion
Osmosis
Translocation
Imbibition
Which of the following is NOT a major driving force for long-distance transport in plants?
Transpiration pull
Root pressure
Active transport
Diffusion
Which of the following is NOT a characteristic of the apoplastic pathway?
Movement through cell walls
Movement through intercellular spaces
Unregulated movement until the Casparian strip
Movement through plasmodesmata
The pressure-flow hypothesis explains the translocation of sugars in the phloem. Which of the following statements regarding this hypothesis is INCORRECT?
Active loading of sugars at the source creates a high solute concentration in the sieve tubes.
Water moves from the xylem to the phloem at the source, increasing turgor pressure.
Sugars are unloaded at the sink, lowering the solute concentration and water potential.
Water moves from the sink to the source via the phloem, driven by a pressure gradient.
Which tissue is responsible for the transport of sucrose from leaves to other parts of the plant?
Xylem
Phloem
Cambium
Pith
What is the main form in which sugar is transported in phloem?
Glucose
Fructose
Sucrose
Starch
Water moving through the apoplast encounters a barrier that forces it into the symplast. This barrier is located in which tissue layer of the root?
Epidermis
Cortex
Endodermis
Pericycle
If transpiration in a plant is significantly reduced, which of the following is MOST likely to occur?
Increased water uptake by roots
Decreased leaf temperature
Increased transport of minerals
Increased leaf temperature
The movement of minerals through the apoplast is interrupted at the:
Epidermis
Cortex
Casparian strip
Phloem
Given below are two statements:
Statement I: The transpiration pull generated by water loss can create enough tension to lift a xylem-sized column of water over 130 meters high.
Statement II: Transpiration plays a significant role in cooling leaf surfaces, sometimes by 10 to 15 degrees, due to evaporative cooling.
In the light of the above statements, choose the most appropriate answer from the options given below:
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
