Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/13

Click to flip

13 Cards in this Set

  • Front
  • Back
What is the primary force behind moving water upward through the xylem?
Transpiration (water evaporating out of the top of the plant).
What are aquaporins?
Water channels in cell membranes.
What are "potentials"?
Ways of representing free energy that are used to predict which way water will move across a membrane.
What are the two components to water potential?
Physical forces (pressure potential) and solute concentrations (solute/osmotic potential).
Water potential is equal to _______ plus ________. Does water move toward more negative or more positive water potentials?
Pressure potential. Solute potential. More negative.
What is the method of moving water up the xylem by actively transporting ions into the roots, increasing their solute potential?
Root Pressure. It is used when transpiration cannot occur.
What is guttation? Under what circumstances does it occur?
The evacuation of water from leaves through specialized veins. When the plant is using root pressure to transport water.
What is cohesion? Adhesion?
The tendence of water to stick to itself (hydrogen bonds). The tendency of water to stick to other things.
Stomata are meant to let ________ out and ________ in.
Water vapor. CO2.
What are aerenchyma? What problem do they solve?
Loose parenchymal tissue with large air spaces. They allow the transport of oxygen, preventing the suffocation of plants in flooded areas.
What is translocation?
The transport of carbohydrates throughout the plant.
What is the theory concerning the mechanism of translocation?
The mass-flow hypothesis (aka pressure flow hypothesis or bulk flow hypothesis).
What does the mass-flow hypothesis state?
Carbohydrates at a "source" area are forced into small phloem tubes by phloem loading. Water diffusion and turgor pressure take the carbohydrates to the "sink".