What are macronutrients referred to?
They are needed in large quantities by the plant.
Signal deactivation
when no more signal is received by the signal receptor and signal transduction stops
Second messengers
small molecules produced rapidly to amplify signal transduction and response
Ion channels
channel protein allowing passage of specific ions through the plasma membrane down an electrochemical gradient
Enzyme
linked receptors- transmembrane protein activated in signal transduction and responsible for starting the phosphorylation cascade
Signal receptors
specialized protein in plasma receiving signals from outside the cell and binding to a signal molecule
Signal transduction
conversion of a signal from outside the cell to within the cell
Ligands or signal molecules
influx of ions triggers a response
Phosphorylation cascade
number of phosphorylation events triggered by enzymes as a result of signal transduction to amplify a signal through the plasma membrane
G
proteins- amplify signal in signal transduction and produce large amounts of second messengers
Phototropism
movement or growth of a plant in response to light (positive is towards light, negative is away from)
Gravitropism
movement of a plant in response to gravity (positive is with gravity, negative against gravity)
Climacteric
fruits that have high respiration rates during ripening and concurrent high ethylene production
Non
climacteric- ripen gradually without the surge of ethylene followed by a surge of CO2
Salicylic acid
induces proteins in response to pathogen attacks on older leaves, system acquired resistance, enhances flower longevity and inhibits ethylene production and seed germination
Brassinosteriods
promote cell division and elongation, stimulate phloem and xylem development and fertility, promote ethylene production, inhibit root growth
Hypersensitive response
plant defense mechanism where cells intruded by pathogen will kill themselves and surrounding cells to starve the pathogen
Active ion exclusion
metallothioneins inactivate metalions, antiporters moe toxic ions into the vacuole
Water potential
the energy of water in an environment, solute potential + pressure potential
Guttation
root pressure forces excess water out of leaf
Transpiration
loss of water vapor through the stomata in the leaves
Phytoremediation
using plants for the reduction or removal of contaminants from soil, water, or air
Passive ion exclusion
casparian strip in endoderm, transporter proteins, limit which ions can enter
Pressure potential
the force applied by the cell wall from the inside in response to pressure from water entering the cell
Soil amendment
can be added to soil to help with levels of macro or micronutrients
Foliar application
nutrients can be sprayed on the leaves in a solution rather than applied to the soil
Turgor pressure
when water enters the central vacuole and causes it to swell and exert pressure against the cell wall
Symplast
the pathway that leads through cells and plasmodesmata that connect adjacent cells
Apoplast
the pathway through the porous cell walls and spaces in between cells
Solute potential
part of water potential and refers to the difference in energy of water based on the solute concentration, values are negative
Osmosis
diffusion of water across a semipermeable membrane in the direction from high water potential to low water potential until equilibrium between solutions is reached
Hypotonic
lower solute potential and higher water potential than inside the cell, water moves into cell, plant cells become turgid
Hypertonic
higher solute potential and lower water potential than inside cell, water moves out of the cell, plant cells become plasmolyzed
Active transport
primary (protein pumps) and secondary (cotransporters and exchange)
Diffusion
movement of particles from an area of high concentration to low concentration
Field capacity
percentage of water held in a soil saturated with water and drained
A horizon
mineral soil mixed with some organic matter, topsoil
Water holding capacity
amount of water a soil can hold based on the soil texture
Clay
less than 0.002 mm
O horizon
partly decayed organic matter
C horizon
soil parent material is little weathered and extends down to bedrock
Saturation
has too much water
B horizon
mineral soil with clay moved from A horizon, subsoil
Permanent wilting point
percentage of soil moisture below which plants cannot absorb more water and begin to wilt
Silt
0.002-0.02 mm
Sand
0.02- 2 mm
The Soil Particles that made up a loam are
Sand, silt, and clay
Which of the following statements about soil is false?
The B horizon is called the top soil.
Very Sandy soils are not desirable for plant growth because
They do not hold minerals or water well
Field capacity is the
Percentage of water remaining in a soil after excess moisture has drained.
Which of the following is not a micronutrient?
Nitrogen.
Which of the following is not a factor of soil formation?
Surface vegetation
The cultivation of plants with their roots in a nutrient solution is called?
Hydroponics
Which of the following is not a popular media used to anchor root systems?
Peanut hulls
What nutritional level is present if there are no visible deficiency symptoms in plants, but there is reduced plant growth due to limited fertility?
Sub-optimal
This plant hormone mediates plant response to light and gravity?
Auxin
When a plant responds to light either by growing away or toward it, this phenomenon is called?
Phototropism
Which of the following would not occur during signal recognition?
The signal molecule is being transported into the cell to induce cellular responses.
Dwarf mutant plants are short because they:
cannot synthesize gibberellin
These two hormones can control root and shoot formation of an initial ex-plant in tissue culture
Auxin and Cytokinin
Photoperiodism is the biological response to changes in
Day length, or photoperiod.
This plant hormone promotes stem elongation, induces seed germination, fruit set and growth. It also promotes maleness in dioecious flowers.
Gibberellin
When an external signal is converted to a signal inside the cell, the process is called?
Signal transduction
Which of the following statements are true?
Statements A & B
(A. Abscisic acid induces dormancy in seeds and buds
B. Abscisic acid is involved in the closing of stomata in a plant experiencing water stress.)
Fruit growers have to be careful to keep the levels of the hormone low around their fruits in order to slow the ripening process
Ethylene
_______ refers to the movement of water across a semi-permeable membrane from high water potential to low water potential
Osmosis
The effect of transpiration is to
Create a tension to pull water upward in the Xylem.
_______ refers to the pathway the water moves through cells and plasmodesmata the connected them.
Symplast.
_______ explains how the negative pressure caused by the pool of transportation moves water from the roots all the way up to the canopy of tall trees
The cohesion- Tension theory.
Water is able to move through the plant as an unbroken column of water because of waters attraction to other water molecules. This property of water is known as
Cohesion
An example of cation exchange is ____ replacing ____ on a clay particle
H+;K+
Most of the minerals in the soil are?
Attracted to the soil particles.
This term refers to the concentration of solutes compared to pure water and is represented by the Greek letter (??)s
Solute potential
Guttation is due to?
Root pressure
Plant roots decrease soil PH and release _____ into the spoil solution to make more available for uptake.
H+ (Protons)