What is the main form in which sugar is transported in phloem?
Glucose
Fructose
Sucrose
Starch
Related Questions
A plant is exposed to a chemical that specifically inhibits the activity of aquaporins in root cells. Which of the following would be the MOST direct consequence of this inhibition?
Increased rate of transpiration
Enhanced mineral absorption
Stimulation of phloem loading
Reduced water uptake by the roots
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
Transpiration contributes to the cooling of leaf surfaces. This cooling effect can be as much as:
2°C
10°C
20°C
30°C
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
The cohesion-tension theory explains the ascent of sap in the xylem primarily due to:
Root pressure
Capillary action
Active transport of water
The cohesive properties of water and transpiration pull
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.
Girdling experiments demonstrate the role of which tissue in the transport of sugars?
Phloem
Xylem
Cambium
Pith
Girdling experiments, where the bark of a tree is removed in a ring around the trunk, demonstrate the importance of phloem for translocation. Which observation is NOT expected after girdling?
Accumulation of sugars above the girdle.
Swelling of the bark above the girdle.
Eventual death of the roots due to lack of nutrients.
Increased sugar concentration above the girdle and decreased sugar concentration below the girdle, with no effect on xylem function.
Which of the following correctly describes the apoplastic pathway in plants?
Movement through the cytoplasm
Movement through plasmodesmata
Movement through cell walls and intercellular spaces
Movement across cell membranes
