Ag Crop Physiology Exam 2 cards

• These bonds; act like rubber bands that can absorb energy from heat providing a ---- to temperature fluctuations; connect to ionic substances such as mineral nutrients increasing their ---- for uptake by the roots; form between water molecules creating a strong interaction or ---- so they are not easily pulled apart and form to solid surfaces or ---- important for movement of water through the ----.

  Buffer, Solubility, Adhesion, cohesion, xylem

• Diffusion occurs through the plasmamembrane primarily through _______ from a _______ to a _______ water potential.

  Aquaporins/high/low
• True or False. Living cells have positive pressure, while the xylem (dead tissue) has negative pressure (tension).

  True
• An example of a stomatal control mechanism causing the opening of the stomatal pore would be:

  H+ ions pumped out of guard cells creating an electrochemical gradient
• Roots [---] water through the [---]. Water can flow through the [---] or apoplast pathway or through the [---] or symplast pathway to the endodermis. Water must move through the plasmamembrane of the endodermis because these cells are impregnated with lignin called the [---]. From the endodermis water moves into the [---] in the vascular cambium

  adsorb, epidermis, cell walls, cytoplasm, casparian strip, xylem.
• At what parts of the continuum of water movement through a tree would there be the most negative pressure potential and the most negative water potential?

  Leaf xylem and the outside air
• Water constitutes what percent of plant tissues?

  80-90%
• pressure gradient / bulk flow


  A _______ is responsible for water movement through soil and xylem cells of the vascular system and is called _______?
• Hydrogen bond


  The opposite partial charges of the oxygen and the hydrogen of water molecule create an electrostatic attraction between water molecules to form what type of bond?
• True


  Osmosis is dependent upon changes in the water potential. If the water potential on the outside of a cell is -0.352 MPa and the water potential inside the cell is -0.6653 MPa water will move into the cell.
• Xylem / mesophyll cell walls / water vapor


  Water diffuses from the ________ into the _________ and evaporates into the innercellular spaces of the leaf as _________.
• All of the above: Nutrient Uptake, Photosynthesis, Evaporating cooling


  What processes do transpiration assist with in maintaining plant health?
• Iron


  Which of the following elements helps form parts of certain enzymes and proteins in electron transport?
• Nitrogen


  Which of the following elements is considered mobile within the plant?
• False


  Elements that move through the phloem from old leaves to the younger leaves are considered immobile. (T/F)
• Calcium


  This ion is important to the structural integrity of the cell wall and thus distorted, newly formed leaves is deficiency symptom.
• NH4


  In a Hoagland solution, nitrogen is supplied as both NO3 and ___________.
• Calcium


  Which mineral nutrient is a constituent of the middle lamella of cell walls and also acts as a second messenger in metabolic regulation?
• Potassium


  What nutrient element is responsible for the activation of over 60 different enzymes?
• Nitrogen and Phosphorous


  What two macronutrients are the primary elements that make up energy storing compounds?
• Bulk Flow and Diffusion


  Nutrients can move to the root surface via:
• Zinc


  This nutrient element is important in the formation of IAA, a growth hormone involved in stomate opening and closing, and deficiency symptoms rosetting and leaf puckering.
• 5.5 - 6.5


  The majority of elements are available to the plant within which pH range?
• True


  Cations bind to negatively charged soil particles. (T/F)
• Magnesium


  A deficiency in which of the following elements could result in interveinal chlorosis of the older leaves?
• Boron


  What is one of the micronutrients obtained from the soil?
• Magnesium


  The deficiency symptom of this nutrient element is interveinal chlorosis central as one of its primary functions is the central ion of the chlorophyll molecule.
• 90%

  The average root system is 20 to 50% of total plant weight, however the root system of a nutrient starved plant can be ________ of total plant weight.
• False


  Shade plants or plants grown under low light levels have increased mycorrhizae.(T/F)
• Dry; increased


  ________ soils = _________ root mass
• False


  The Proton Motive Force is stored free energy in the form of the Ca+ gradient creating active transport across the membrane. (T/F)
• Vesicular-arbuscular


  Which type of mycorrhizae is found only in herbaceous angiosperms?
• All of the above:

  -protons are pumped from the cytosol by an ATPase creating a proton gradient.

  -there is an electrochemical gradient created to move substances in the same direction.

  -there is an electrochemical gradient created to move substances in the opposite direction.


  Secondary active transport occurs when __________ across the membrane.
• Plasmodesmata


  What are the tubular structures that extend through adjacent cell walls and middle lamella from cytosol to cytosol?
• True


  Aquaporins is a membrane protein that primarily transports water and function as sensors of gradients in regulating osmotic potential and turgor pressure.(T/F)
• Proteinaceous Carriers


  Which type of membrane protein combines with a specific solute on one side of the membrane and then through a conformational change, releases the solute on the other side?
• combines with


  ATPase ___________ the proton to move it across the membrane.
• is a protein pump coupled directly to an energy source

  Primary active transport:
• highly selective and can transport ions as well as metabolites such as flavenoids, anthocyanins, growth hormones and secondary metabolites

  Protein transporters are:
• True


  Mycorrhizae have a symbiotic relationship with plants; the fungus receives organic nutrients from the plant while the fungal hyphae aid in the plant's absorption of mineral nutrients.(T/F)