Term
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Definition
| movement of substances (molecules) through a medium from high to low concentration due to kinetic energy- motion |
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Term
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Definition
| movement of solvent through a semipermeable membrane from a region of high to low solvent concentration |
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Term
| Is the plasma membrane semipermeable? |
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Definition
| NO, it is differentially permeable (some stuff gets through; some doesn't) |
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Term
| Explain osmotic potential |
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Definition
| osmotic pressure that could develop |
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Term
| What does an osmometer do? |
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Definition
| It measures osmotic pressure |
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Term
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Definition
| the cell membrane pulls away from the cell wall due to osmosis |
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Term
| Explain Incipient Plasmolysis |
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Definition
| The state of a plant cell in which the turgor pressure is zero |
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Term
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Definition
| The chemical energy level or chemical potential of water |
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Term
| How is water potential measured? |
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Definition
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Term
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Definition
| loss of water in the vapor state (or by evaporation) from plant tissues |
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Term
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Definition
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Term
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Definition
| stress hormone from water |
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Term
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Definition
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Term
| WHat are the components of plant water potential? |
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Definition
Ψw= water potential
Ψp= turgor or pressure potential
Ψs= solute or osmotic potential |
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Term
| What happens to transpiration when there is a lower Relative Humidity? |
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Definition
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Term
| What happens to transpiration when there is a higher Relative Humidity? |
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Definition
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Term
| Explain the Mechanism of Stomatal Action |
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Definition
| Light --> malicacid production --> dissociates into H+ and Malate --> Influx of K+ with Efflux of H+ via a H+/K+ plasma membrane to create K+ and malate (a Salt) --> K+ malate transported to central vacuole --> osmosis of H2O from adjacent cells --> turgor --> OPEN Stomata |
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Term
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Definition
| ABA causes roots stress; stressed roots cause process to reverse and close the stomatas |
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Term
| List the methods to measure transpiration rates |
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Definition
1) Cobal + Chloride
2) Potometer (lab device)
3) Weight change method
4) Closed chamber or cuvette method
5) Diffusive Resistance Porometer
6) Stem flow method |
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Term
| Explain the path of water in transpiration |
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Definition
| Water is absorbed in the root hairs, then the water migrates to the cortex, then to the endodermis, then to the pericycle, then to the stem xylem, then to the leaf xylem, then to the leaf mesophyll, then to the substomatal cavity, then out through the stomata |
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Term
| Name the methods of measuring plant water potential |
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Definition
1) Weight change method
2) Falling Drop Method
3) Pressure chamber method
4) Vapor Pressure method |
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Term
| Explain the Weight Change Method of measuring plant water potential |
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Definition
1) cut out plugs of potato tissue (uniform length/width)
2) measure plugs to obtain initial weight
3) place plugs in various solutions
4) wait a certain amount of time in order for changes to occur
5) remove plugs from solutions, use blot tissue to dry plugs, weigh plugs for final weight
6) |
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