The primary mechanism for xylem sap ascent in tall trees is transpiration pull. However, root pressure plays a minor role. Which statement BEST describes the limited contribution of root pressure to overall xylem sap ascent in tall trees?
Root pressure generates excessive pressure that could damage the delicate xylem tissues in tall trees.
Root pressure is only active during the night and therefore cannot contribute to daytime transpiration.
Tall trees have a significantly lower root surface area to volume ratio, minimizing the contribution of root pressure.
Root pressure can only push water a limited height due to the opposing force of gravity and the relatively low pressure generated.
Related Questions
A researcher applies a potent respiratory inhibitor to the root cells of a plant. Which of the following would be MOST directly affected, ultimately impacting root pressure?
Water potential gradient between the soil and root hairs
Cohesion and adhesion of water molecules in the xylem
Transpiration pull from the leaves
Active transport of ions into the xylem
Root pressure is most likely to be observed in which of the following conditions?
High temperature and high transpiration
High humidity and low transpiration
Strong winds and high light intensity
Dry soil and low humidity
    Examples of bulk flow by a positive hydrostatic pressure gradient and a negative hydrostatic pressure gradient are
Suction through straw and swelling of wood, respectively
Imbibition and a garden hose
    Garden hose and suction through a straw, respectively
    Swelling of wood and imbibition, respectively
Guttation, the exudation of water droplets from leaves, is most likely to occur when:
Root pressure is low and transpiration is high.
Root pressure is high and transpiration is high.
Root pressure is low and transpiration is low.
Root pressure is high and transpiration is low.
If the stomata of a plant leaf are blocked, which process would be most directly affected, hindering the plant's ability to produce glucose?
Transpiration
Respiration
Photosynthesis
Nutrient absorption
If the root pressure of a plant is measured to be slightly acidic, which ion transport mechanism is most likely responsible for this acidity?
Active transport
Passive transport
Passive transport
Active transport
Root pressure is typically highest under which of the following conditions?
High soil moisture and high transpiration rate
Low soil moisture and low transpiration rate
Low soil moisture and high transpiration rate
High soil moisture and low transpiration rate
Root pressure primarily contributes to the movement of water in:
Tall trees
Short plants and herbs
Desert plants
Submerged aquatic plants
If the water potential of root cells is -0.5 MPa and the water potential of the xylem sap is -0.7 MPa, which statement BEST describes the movement of water?
Water will move from the xylem into the root cells
Water will move from the root cells into the xylem
There will be no net movement of water
Water will move equally in both directions
A plant exhibits vigorous guttation during the night. Which of the following would be the MOST likely consequence of completely sealing the hydathodes with a waterproof sealant without harming the plant otherwise?
A significant decrease in root pressure
A substantial increase in transpiration rate
No change in root pressure or transpiration rate
A slight increase in root pressure
