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
Related Questions
The movement of minerals through the apoplast is interrupted at the:
Epidermis
Cortex
Casparian strip
Phloem
The pressure-flow hypothesis explains the movement of:
Sugars in phloem
Water in xylem
Minerals in xylem
Water in phloem
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.
What is the main form in which sugar is transported in phloem?
Glucose
Fructose
Sucrose
Starch
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
A researcher is studying long-distance transport in a plant. They introduce a radioactive tracer into the phloem sap of a source leaf. Which of the following would LEAST likely be observed after a period of time?
Movement of the tracer towards a developing fruit
Presence of the tracer in the root tips
Detection of the tracer in a sink leaf
Significant accumulation of the tracer in mature xylem vessels of the source leaf
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
Transpiration contributes to the cooling of leaf surfaces. This cooling effect can be as much as:
2°C
10°C
20°C
30°C
Which of the following is NOT a long-distance transport pathway in plants?
Xylem
Phloem
Apoplast
Symplast
The upward movement of water in tall trees is primarily driven by:
Root pressure
Capillary action
Transpiration pull
Active transport
