The upward movement of water in tall trees is primarily driven by:
Root pressure
Capillary action
Transpiration pull
Active transport
Related Questions
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
Which process is primarily responsible for the loading of sucrose into sieve tube elements?
Active transport
Diffusion
Osmosis
Passive transport
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
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
What is the main form in which sugar is transported in phloem?
Glucose
Fructose
Sucrose
Starch
The Casparian strip in the endodermis primarily restricts the movement of water via the:
Apoplast
Symplast
Transmembrane pathway
Vacuolar pathway
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
Which combination of factors would MOST effectively enhance the rate of transpiration in a plant?
Low light intensity, high humidity, open stomata, and still air
High light intensity, high humidity, closed stomata, and strong wind
Low light intensity, low humidity, closed stomata, and still air
High light intensity, low humidity, open stomata, and strong wind
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, 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.
