Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
Plants must always compromise between _____ and _____.
maximizing water loss ... minimizing H+ protons maximizing transport of minerals ... minimizing transport of sugars maximizing photosynthesis ... minimizing water loss maximizing access to light ... minimizing intake of CO2 maximizing water absorption ... minimizing leaf area |
maximizing photosynthesis ... minimizing water loss
|
|
|
A plant cell placed in a solution with a lower (more negative) water potential will _____.
lose water and plasmolyze gain water and plasmolyze gain water and become turgid lose water and burst lose water and become turgid |
lose water and plasmolyze
|
|
|
Which of the following is a correct statement about a difference between xylem and phloem transport? Transpiration moves phloem sap but not xylem sap. Xylem sap moves up; phloem sap moves up or down. Active transport moves xylem sap but not phloem sap. Xylem sap moves from sugar source to sink, but phloem sap does not. Phloem carries water and minerals; xylem carries organic molecules. |
Xylem sap moves up; phloem sap moves up or down. |
|
|
A student is performing a chemical analysis of xylem sap. This student should not expect to find much _____. phosphorus sugar water nitrogen potassium |
sugar |
|
|
Which one of the following refers to the loss of water through the stomata in a plant's leaves? bulk flow guttation transpiration osmosis respiration |
transpiration |
|
|
In addition to transporting sugar, the phloem also _____. transmits electrical signals transports viral RNA throughout the plant transports plant RNA throughout the plant transports proteins throughout the plant All of the above |
All of the above |
|
|
Which structure or compartment is part of the symplast? the cell wall of a root hair the interior of a vessel element an extracellular air space the cell wall of a mesophyll cell the interior of a sieve tube |
the interior of a sieve tube |
|
|
Movement of phloem sap from a source to a sink depends on tension, or negative pressure potential. depends on pumping water into sieve tubes at the source. occurs through the apoplast of sieve-tube elements. depends ultimately on the activity of proton pumps. results mainly from diffusion. |
depends ultimately on the activity of proton pumps |
|
|
Photosynthesis ceases when leaves wilt, mainly because accumulation of CO2 in the leaf inhibits enzymes. stomata close, preventing CO2 from entering the leaf. the chlorophyll in wilting leaves is degraded. flaccid mesophyll cells are incapable of photosynthesis. photolysis, the water-splitting step of photosynthesis, cannot occur when there is a water deficiency. |
stomata close, preventing CO2 from entering the leaf. |
|
|
Which of the following would tend to increase transpiration? a rainstorm spiny leaves higher stomatal density sunken stomata a thicker cuticle |
higher stomatal density |
|
|
Select the accurate statement about water potential. Free water moves from a region of lower water potential to a region of higher water potential. Adding solutes to water increases water potential. Water in a turgid cell has positive pressure potential. |
Water in a turgid cell has positive pressure potential. |
|
|
Select the correct mechanism of stomatal opening and closing.
The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid. Light stimulates proton pumps in the plasma membrane of the guard cells, causing them to lose K+ and become flaccid. The cell walls of guard cells are thickened on the side of the stomatal opening and the thinner walls bow outward when the guard cells become turgid, to close the stomata. |
The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid.
|
|
|
If a plant’s stomata are closed and no transpiration is occurring, which of the following predictions is accurate?
Without transpiration, the plant will be water deficient. Without transpiration, the plant’s cells will become flaccid. Without transpiration, less water will be absorbed from the soil. |
Without transpiration, less water will be absorbed from the soil.
|
