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13 Cards in this Set
- Front
- Back
What is a water potential?
What are its two components? |
Movement of water from an area of high concentration to an area of low concentration
1.) Solute potential (water becomes more negative with higher concentrations of a solute) 2.) Pressure potential |
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What is turgid?
what is Plasmolyzed? |
Turgid - A cell expanding by water uptake
Plasmolyzed - Cell shrinkage by water loss. |
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Explain water uptake in plants
Where is water unregulated? Where is water regulated? |
Water moves into the cortex (lower water potential than soil), then moves into the vascular cylinder (lower water potential than cortex)
Unregulated - In the Apoplast Regulated - By Plasma Membrane in the Symplast (forced into symplast by casparian strips) |
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What is the effect of water evaporating from the open stomata?
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Makes the water potential of mesophyll cells more negative, and causes water to enter the cell osmotically from the vein.
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How does water move down to the roots?
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The cohesion of water molecules, will form an adhesion to the dead cell walls.
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Describe what is required for a guard cell to open? What products come into the cell, and when do they leave?
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The cell opens when it is turgid. This is done by having potassium ions (K+) to enter the guard cell which allows for the water to move into the guard cell and fill the vacuoules (opening the stomata)
The stomata closes when the potassium ions leave, causing the water to leave too. |
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What can influence water loss?
And what is the role of transpiration in a beneficial way? |
Water loss is influenced by the cuticle and the stomata
Transpiration - Evaporative loss of water from plant shoot Benefits: Distributes water to upper parts of plant, and cools leaves warmed by the sun's radiation. |
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What influences Transpiration?
(2 main things) |
1.) Stomatal opening/ closing
2.) Evironmental conditions (air temperature, and relative humidity) |
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When do plants open and close their stomata? and under what conditions?
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Plants open their stomata during the day and close them at night
The stomata will open if the CO2 concentration inside the leaf air spaces is too low The stomata will close if the plant is extremely water stressed. |
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Name 4 things of phloem transport (Translocation)
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1.) Requires living phloem tissue
2.) Can occur in either direction (up or down) 3.) Involves ATP energy 4.) It is mostly sucrose (about 90% sugar) |
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Transport of photosynthate occurs from ..... to.....
And has its highest concentration at the..... |
Source to Sink
Source |
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How is sucrose loaded into the phloem?
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By Active Transport
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What type of "transporting" do solutes use to move from the phloem to the sink?
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Active Transport.
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