Enter a player name to begin or load your saved progress.
Water-use efficiency (WUE) in plant physiology is fundamentally defined as the ratio of plant biomass produced to the amount of water lost by the plant through transpiration.
Answer: True
Explanation: The fundamental definition of Water-use efficiency (WUE) in plant physiology is the ratio of plant biomass produced to the amount of water lost through transpiration.
At the leaf level, instantaneous water-use efficiency (WUEinst) is the ratio of the rate of net CO2 carbon assimilation to the rate of water absorption from the soil.
Answer: False
Explanation: Instantaneous water-use efficiency (WUEinst) at the leaf level is defined as the ratio of net CO2 carbon assimilation to the rate of transpiration, not water absorption from the soil.
Intrinsic water-use efficiency (iWUE or Wi) is calculated as the ratio of the rate of net CO2 carbon assimilation to the rate of stomatal conductance.
Answer: True
Explanation: Intrinsic water-use efficiency (iWUE or Wi) is precisely defined as the ratio of net CO2 carbon assimilation to stomatal conductance.
Water-use efficiency of productivity is exclusively known as transpiration efficiency (TE) and does not have other alternative terms.
Answer: False
Explanation: Water-use efficiency of productivity is also known as integrated water-use efficiency, in addition to transpiration efficiency (TE).
Water-use efficiency (WUE) in plant physiology is synonymous with 'Water efficiency,' which refers to water use efficiency by humans.
Answer: False
Explanation: Water-use efficiency (WUE) in plant physiology is explicitly distinguished from 'Water efficiency,' which refers to water utilization efficiency by humans, and is not synonymous.
Water-use efficiency (WUE) can be defined at the leaf level, the whole plant level, or at a larger scale such as a population or field level.
Answer: True
Explanation: Water-use efficiency (WUE) can indeed be defined at multiple hierarchical levels, including the leaf level, the whole plant level, or at larger scales such as a population, stand, or field level.
Photosynthetic water-use efficiency at the leaf level is also known as integrated water-use efficiency.
Answer: False
Explanation: Photosynthetic water-use efficiency at the leaf level is also known as instantaneous water-use efficiency (WUEinst), not integrated water-use efficiency.
At the plant level, water-use efficiency of productivity is defined as the ratio of the dry biomass produced by the plant to the rate of transpiration.
Answer: True
Explanation: At the whole-plant level, water-use efficiency of productivity is precisely defined as the ratio of the dry biomass produced by the plant to the total amount of water transpired.
Water-use efficiency (WUE) is generally expressed as a ratio comparing the amount of plant biomass created to the quantity of water transpired by the plant.
Answer: True
Explanation: Water-use efficiency (WUE) is generally expressed as a ratio comparing the amount of plant biomass created to the quantity of water transpired by the plant, reflecting how effectively a plant converts water into growth.
Dry biomass refers to the total mass of organic matter in the plant including all water content.
Answer: False
Explanation: Dry biomass refers to the total mass of organic matter in the plant after all water content has been removed, not including it.
Stomatal conductance refers to the degree to which stomata are open, controlling the exchange of gases and water vapor.
Answer: True
Explanation: Stomatal conductance quantifies the degree to which stomata are open, thereby regulating the exchange of gases and water vapor between the plant and the atmosphere.
What is the fundamental definition of Water-use efficiency (WUE) in plant physiology?
Answer: The ratio of plant biomass produced to the amount of water lost through transpiration.
Explanation: The fundamental definition of Water-use efficiency (WUE) in plant physiology is the ratio of plant biomass produced to the amount of water lost by the plant through transpiration.
At which of the following levels can Water-use efficiency (WUE) be defined?
Answer: At the leaf level, whole plant level, or larger scales like a population or field.
Explanation: Water-use efficiency (WUE) can be defined at multiple hierarchical levels, including the leaf level, the whole plant level, or at larger scales such as a population, stand, or field level.
What is another name for photosynthetic water-use efficiency at the leaf level?
Answer: Instantaneous water-use efficiency (WUEinst).
Explanation: Photosynthetic water-use efficiency at the leaf level is also referred to as instantaneous water-use efficiency (WUEinst).
How is intrinsic water-use efficiency (iWUE or Wi) calculated?
Answer: Ratio of net CO2 carbon assimilation to stomatal conductance.
Explanation: Intrinsic water-use efficiency (iWUE or Wi) is defined as the ratio of the rate of net CO2 carbon assimilation to the rate of stomatal conductance.
Water-use efficiency (WUE) in plant physiology is distinguished from what other concept?
Answer: 'Water efficiency,' referring to human water use.
Explanation: Water-use efficiency (WUE) in plant physiology is explicitly distinguished from 'Water efficiency,' a term that refers to water utilization efficiency by humans.
How is water-use efficiency (WUE) generally expressed as a ratio?
Answer: Comparing the amount of plant biomass created to the quantity of water transpired.
Explanation: Water-use efficiency (WUE) is generally expressed as a ratio comparing the amount of plant biomass created to the quantity of water transpired by the plant.
What is the definition of transpiration in the context of WUE?
Answer: The process where plants release water vapor into the atmosphere, primarily through stomata.
Explanation: Transpiration is the process where plants release water vapor into the atmosphere, primarily through small pores on their leaves called stomata.
What does stomatal conductance refer to?
Answer: The degree to which stomata are open, controlling gas and water vapor exchange.
Explanation: Stomatal conductance quantifies the degree to which stomata are open, thereby regulating the exchange of gases and water vapor.
What are alternative terms for water-use efficiency of productivity?
Answer: Integrated water-use efficiency or transpiration efficiency (TE).
Explanation: Water-use efficiency of productivity is also known as integrated water-use efficiency or transpiration efficiency (TE).
Intrinsic water-use efficiency (Wi) typically decreases during periods of soil drought due to increased stomatal opening.
Answer: False
Explanation: Intrinsic water-use efficiency (Wi) typically increases during periods of soil drought, primarily due to stomatal closure, which reduces water loss.
High water-use efficiency plants are generally associated with a drought avoidance or water saving strategy.
Answer: True
Explanation: High water-use efficiency plants are indeed typically associated with a drought avoidance or water saving strategy, enabling them to conserve water during arid periods.
A drought escape strategy involves plants completing their life cycle through early flowering before severe drought conditions intensify.
Answer: True
Explanation: A drought escape strategy is characterized by plants completing their life cycle, often through accelerated flowering, prior to the onset or intensification of severe drought conditions.
Low water-use efficiency plants might exhibit drought tolerance through anatomical adaptations that increase their vulnerability to xylem cavitation.
Answer: False
Explanation: Low water-use efficiency plants may exhibit drought tolerance through anatomical adaptations that diminish their vulnerability to xylem cavitation, not increase it.
Drought-sensitive, early closing stomata in high WUE plants help conserve water by quickly reducing water loss through transpiration.
Answer: True
Explanation: Drought-sensitive, early closing stomata in high WUE plants contribute to a water-saving strategy by promptly reducing water loss through transpiration upon the initiation of soil water deficits.
Increases in water-use efficiency are considered an important plant response to moderate to severe soil water deficits because they allow for less biomass production per unit of water consumed.
Answer: False
Explanation: Increases in water-use efficiency are considered a crucial plant response to soil water deficits because they enable plants to produce a greater amount of biomass per unit of water consumed, not less.
Intrinsic water-use efficiency is often linked to a plant's ability to absorb more water from the soil during drought.
Answer: False
Explanation: Intrinsic water-use efficiency is frequently associated with drought tolerance, which often involves water conservation mechanisms like stomatal closure, rather than an increased ability to absorb water from the soil during drought.
Low water-use efficiency plants might employ a drought avoidance strategy through a wide soil exploration by roots.
Answer: True
Explanation: Low water-use efficiency plants may indeed employ a drought avoidance strategy through extensive soil exploration by roots, enabling greater water acquisition.
Observations have suggested that water-use efficiency (WUE) is a simple, direct indicator of drought tolerance.
Answer: False
Explanation: Empirical observations indicate that water-use efficiency (WUE) is intricately linked to diverse drought response strategies, rather than serving as a simplistic, direct indicator of overall drought tolerance.
How does intrinsic water-use efficiency (Wi) typically respond during soil drought conditions?
Answer: It usually increases due to stomatal closure.
Explanation: Intrinsic water-use efficiency (Wi) typically exhibits an increase during periods of soil drought, primarily due to stomatal closure and a subsequent reduction in transpiration.
What plant characteristic is intrinsic water-use efficiency often associated with?
Answer: Drought tolerance.
Explanation: Intrinsic water-use efficiency is frequently associated with drought tolerance, which denotes a plant's capacity to endure prolonged periods of water scarcity.
Which of the following is a drought tolerance strategy that might be associated with low water-use efficiency plants?
Answer: Anatomical adaptations that reduce vulnerability to xylem cavitation.
Explanation: Low water-use efficiency plants may exhibit drought tolerance through anatomical adaptations that diminish their vulnerability to xylem cavitation.
What type of drought response strategy is typically associated with high water-use efficiency plants?
Answer: A drought avoidance or water saving strategy.
Explanation: High water-use efficiency plants are typically associated with a drought avoidance or water saving strategy, possessing adaptations that enable them to conserve water effectively during arid periods.
Why are increases in water-use efficiency commonly cited as an important response mechanism for plants during soil water deficits?
Answer: They allow plants to produce more biomass per unit of water consumed.
Explanation: Increases in water-use efficiency are commonly cited as a crucial response mechanism for plants facing soil water deficits because they enable plants to produce a greater amount of biomass per unit of water consumed.
What physiological mechanism contributes to the increase in intrinsic water-use efficiency during drought?
Answer: Stomatal closure and subsequent reduction in transpiration.
Explanation: The increase in intrinsic water-use efficiency during drought is primarily attributable to stomatal closure and a subsequent reduction in transpiration.
Observations have suggested that WUE is linked to what, rather than being a simple indicator of drought tolerance?
Answer: Different drought response strategies.
Explanation: Empirical observations indicate that water-use efficiency (WUE) is intricately linked to diverse drought response strategies, rather than serving as a simplistic indicator of overall drought tolerance.
How might a drought avoidance or water spender strategy manifest in low WUE plants?
Answer: Through a wide soil exploration by roots or a drought escape strategy due to early flowering.
Explanation: A drought avoidance or water spender strategy in low WUE plants may manifest through extensive soil exploration by roots or through a drought escape strategy characterized by early flowering.
What is a drought escape strategy?
Answer: Plants completing their life cycle, often through early flowering, before severe drought conditions.
Explanation: A drought escape strategy entails plants completing their life cycle, often through accelerated flowering, prior to the onset or intensification of severe drought conditions.
How do drought-sensitive, early closing stomata contribute to a water-saving strategy in high WUE plants?
Answer: They quickly reduce water loss through transpiration when soil water deficits begin.
Explanation: Drought-sensitive, early closing stomata in high WUE plants contribute to a water-saving strategy by promptly reducing water loss through transpiration upon the initiation of soil water deficits.
The eddy covariance technique is primarily used to measure soil moisture content for determining field-level water-use efficiency.
Answer: False
Explanation: The eddy covariance technique is primarily used to measure CO2 and water fluxes over an entire field or forest ecosystem, not soil moisture content, for determining field-level water-use efficiency.
Which technique is used to measure CO2 and water fluxes for field-level water-use efficiency?
Answer: The eddy covariance technique.
Explanation: The eddy covariance technique is employed to measure CO2 and water fluxes for determining water-use efficiency at the field level.
Research to improve water-use efficiency in crop plants has been ongoing since the early 20th century, but has faced difficulties in achieving increased efficiency.
Answer: True
Explanation: Research to enhance water-use efficiency in crop plants has indeed been conducted since the early 20th century, yet it has encountered challenges in effectively achieving substantial increases in efficiency.
The primary goal of many agricultural programs concerning water-use efficiency is to increase crop tolerance to drought.
Answer: True
Explanation: The primary objective of numerous agricultural programs focused on water-use efficiency is to enhance crop tolerance to drought, thereby promoting more stable yields.
The processes of increased crop yield production and decreased water loss due to transpiration are fundamentally complementary in agricultural systems.
Answer: False
Explanation: The processes of increased crop yield production (photosynthetic carbon assimilation) and decreased water loss due to transpiration are fundamentally opposed, not complementary, in agricultural systems.
An ideal situation for crop production would involve increased water-use efficiency leading to lower transpirational rates without decreasing photosynthetic rates and biomass production.
Answer: True
Explanation: An ideal situation for crop production would indeed involve increased water-use efficiency leading to lower transpirational rates without concurrently diminishing photosynthetic rates and biomass production, thereby enabling water conservation without compromising yield.
Since when has research been conducted to improve water-use efficiency in crop plants?
Answer: The early 20th century.
Explanation: Research endeavors aimed at enhancing the water-use efficiency of crop plants have been ongoing since the early 20th century.
What is the primary goal of many agricultural programs concerning water-use efficiency?
Answer: To increase crop tolerance to drought.
Explanation: The primary objective of numerous agricultural programs focused on water-use efficiency is to enhance crop tolerance to drought.
What fundamental opposition exists regarding the benefit of increased water-use efficiency in agricultural systems?
Answer: The opposition between increased yield production and decreased water loss due to transpiration.
Explanation: A fundamental opposition exists concerning the benefit of increased water-use efficiency in agricultural systems because the processes of increased yield production and decreased water loss due to transpiration are inherently antagonistic.
What challenge has been noted in efforts to increase crop water-use efficiency since the early 20th century?
Answer: Difficulties in actually achieving crops with increased water-use efficiency.
Explanation: Despite continuous research efforts since the early 20th century, significant challenges have been encountered in effectively achieving crops with substantially increased water-use efficiency.
What specific processes are fundamentally opposed in the context of increasing crop yield and decreasing water loss?
Answer: Photosynthetic carbon assimilation and transpiration.
Explanation: In the context of optimizing crop yield and minimizing water loss, the processes of photosynthetic carbon assimilation and transpiration are fundamentally opposed.
What ideal situation would make increased water-use efficiency a highly desired trait in crop production?
Answer: If it induced lower transpirational rates without simultaneously decreasing photosynthetic rates and biomass production.
Explanation: Increased water-use efficiency would represent a highly desirable trait in crop production if a scenario could be achieved where water deficit induced lower transpirational rates without concurrently diminishing photosynthetic rates and biomass production.
Water-use efficiency (WUE) is a significant area of study exclusively within agriculture.
Answer: False
Explanation: Water-use efficiency (WUE) is a significant area of study not only within agriculture but also extensively within plant ecology.
Early 20th-century plant ecology research used water-use efficiency to study the ecological requirements of various plant types, including herbaceous plants and forest trees.
Answer: True
Explanation: Early 20th-century plant ecology research indeed employed water-use efficiency to delineate the ecological requirements of diverse plant types, encompassing both herbaceous plants and forest trees.
Current plant ecology research is linking intrinsic water-use efficiency to drought-induced forest decline.
Answer: True
Explanation: Contemporary plant ecology research is actively establishing a link between intrinsic water-use efficiency and the phenomenon of drought-induced forest decline.
The study of water-use efficiency in plant ecology only began in the late 20th century, much later than in agriculture.
Answer: False
Explanation: The investigation of water-use efficiency in plant ecology commenced as early as the 20th century, indicating its long-standing importance, not just a late 20th-century development.
Beyond agriculture, in what other scientific field is water-use efficiency a significant area of study?
Answer: Plant ecology.
Explanation: Beyond its agricultural relevance, water-use efficiency is also an extensively studied trait within plant ecology.
When did the study of water-use efficiency begin in plant ecology?
Answer: As early as the 20th century.
Explanation: The investigation of water-use efficiency in plant ecology commenced as early as the 20th century.
For what purpose was water-use efficiency used in early 20th-century plant ecology research?
Answer: To study the ecological requirements of various plant types.
Explanation: In early 20th-century plant ecology research, water-use efficiency was employed to delineate the ecological requirements of various plant types.
What specific phenomenon is current plant ecology research linking intrinsic water-use efficiency to?
Answer: Drought-induced forest decline.
Explanation: Current plant ecology research is establishing a link between intrinsic water-use efficiency and drought-induced forest decline.