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120 Cards in this Set
- Front
- Back
Naturally occurring Auxin |
Indoleacetic Acid (IAA) |
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Synthetic examples of Auxin |
Indolebutyric Acid (IBA) Naphthaleneacetic Acid (NAA) 2,4-Dichlorophenoxyacetic Acid (2,4-D) |
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Where is Auxin produced? |
Shoot tips and embryos |
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Naturally occurring Cytokinin |
Zeatin Kinetin (not in plants) |
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Synthetic examples of Cytokinin |
Benzyladenine (BA) Pyranylbenzyladenine (PBA) |
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Where is cytokinin produced |
root tips and embryos |
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Naturally occurring Gibberellic Acids (GA) |
over 70!!! |
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SYNTHETIC EXAMPLES OF Gibberellic Acids (GA) |
none |
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where is Gibberellic Acids (GA) produced? |
root tips, shoot tips, embryo |
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naturally occurring ethylene |
ethylene |
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synthetic examples of ethylene |
ethephon or ethrel |
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where is ethylene produced? |
ripening fruit, aging flowers, germinating seeds, wounded tissue |
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naturally occurring abscisic acid |
abscisic acid |
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synthetic examples of abscisic acid |
none |
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where is abscisic acid produced? |
plastids (especially chloroplasts) |
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Tropism |
response of plants to environmental or physical stimuli |
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phototropism |
response to light |
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geotropism |
response to gravity |
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thigmotropism |
response to touch |
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Calorie (cal) |
Amount of heat (heat energy) required to raise 1 g of water by 1 degree C |
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kilocalorie (kcal) |
1,000 calories |
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British Thermal Unit (BTU) |
amount of heat required to raise 1 lb. of water by 1 degree F |
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specific heat |
Amount of heat (# of calories) needed to raise 1 g of a substance 1 degree C |
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specific heat of water |
1.0 |
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heat of fusion |
amount of heat (# calories) needed to change 1 g of a substance from solid to liquid at its melting/freezing point |
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heat of fusion of water |
80 cal/g |
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heat of vaporization |
amount of heat (# of cal) needed to change 1 g of a substance from liquid to gas at its boiling/condensation point |
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heat of vaporization of water |
540 cal/g |
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how is heat transferred? |
conduction, convection, and radiation |
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conduction |
flow of heat energy through a medium from molecule to molecule |
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example of conduction |
touching a hot cup of coffee |
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convection |
mass movement of heat energy |
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example of convection |
blowing hot air into a room to warm it up |
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radiation |
flow of energy as electromagnetic waves, with no transferring medium; when radiation is absorbed it may be converted to heat energy |
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example of radiation |
sun shining through space to warm the earth |
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climate |
the average atmospheric conditions over a long period of time |
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weather |
the current and temporary atmospheric conditions |
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tropical climate zone |
area between 23.5 degrees latitude N and S of equator
between tropic of cancer and tropic of capricorn |
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Temperate climate zone |
The area between 23.5 and 66.5 degrees latitude N, and 23.5 and 66.5 degrees latitude S
Between tropic of cancer and arctic circle, between tropic of Capricorn and Antarctic circle |
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arctic climate zone |
area between 66.5 degrees latitude N and the north pole, and 66.5 degrees latitude S and the south pole
Between arctic circle and north pole, and Antarctic circle and south pole |
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What is at 23.5 degrees latitude N? |
tropic of cancer |
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What is at 23.5 degrees latitude S? |
tropic of Capricorn |
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Summer solstice |
about June 21. Earth's axis is tilted 23.5 degrees toward the sun |
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winter solstice |
about December 21. Earth's axis is tilted 23.5 degrees away from the sun |
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vernal or spring equinox |
About March 21. Earth's axis is oriented oblique to, and neither toward or away from the sun |
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autumnal or fall equinox |
About September 21. Earth's axis is oriented oblique to, and neither toward or away from the sun |
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When is the lowest average temperature of the day? |
Right before sunrise |
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When is the highest average temperature of the day? |
Mid-afternoon |
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cardinal temperature definition |
the temperature range in which plants grow and survive |
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what is the general cardinal temperature of most plants? |
130 F : death 90-96 F : stop growth 78-90 F : optimum temp for warm season plants 65-75 F : optimum temp for cool season plants 40-50 F : stop growth 32-45 F : death of cold sensitive/tropical plants 15-29 F : death of semi-hardy plants < 0 F : death of hardy plants |
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If the temperature today is 45 degrees, the dew point is 35 degrees and the low temp tonight is 28 degrees, what type of frost will happen? |
white frost |
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white frost |
occurs when temp falls below dew point and freezing |
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black frost |
occurs when temp falls below freezing but remains above dew point |
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Radiational Freeze/Frost |
temperature drops due to radiational cooling which results in a temperature inversion; occurs on calm, clear nights |
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dew point |
temperature at which the air reaches 100% relative humidity |
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radiational cooling |
loss of heat by long wavelength infra red radiation |
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temperature inversion |
warm air mass above a cold air mass |
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About how much temp change between day and night on any given day? |
20 degrees F |
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Desiccation |
excessive drying-out of plants due to cold soil and dry winds.
Most common death in winter |
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Ways to prevent a radiational freeze |
Decrease rate of radiational cooling: hot caps or plastic tents, mulches, foams, fog or water vapor, smoke.
Increase air temperature: eliminate temperature inversion (wind machines or helicopters), irrigation (flood irrigation-water is warmer and stabilizes temperature, overhead irrigation-constant temp at 32 degrees F when liquid and ice present), oil burners or smudge pots |
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Ways to prevent an advective freeze |
you can't prevent an advective freeze but you can prevent damage to plants because of one
Plant selection - picking plants that won't die in the coldest average temp in that area
Insulate-mulch, foam, hot caps Increase air temp-irrigation, oil burners, smudge pots
DONT USE fog, smoke, elimination of temp inversion
Site selection-avoid north side of hills etc
Delay development in spring-avoids damage to new growth and flower buds from late spring frosts
Harden-off or cold acclimation in fall-don't encourage growth in fall because plants will go dormant and all new growth will be killed |
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Dormancy |
a state of inactive growth |
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Quiescence Dormancy |
dormancy imposed upon a plant by external or environmental conditions |
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What triggers quiescence? |
unfavorable climate (drought), external factors |
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Rest or Physiological Dormancy |
Dormancy imposed upon a plant by internal or physiological conditions |
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What triggers Rest/Physiological Dormancy? |
Shortening days, decreasing temperature |
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What causes Rest/Physiological Dormancy? |
low levels of growth promoters and/or high levels of growth inhibitors |
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How to overcome Rest/Physiological Dormancy |
Given period between 32-45 degrees F, which satisfies chilling requirement |
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Chilling Requirement |
The number of hours of cold between 32-45 degrees F required to satisfy rest dormancy |
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If Big Daddy Peach is a 300 hour variety and it is planted in College Station (600 hour zone) , what will happen? |
It will flower early and likely be killed by frost |
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Biennial |
Plants that have a two year lifecycle
Rosettes and bluebonnets |
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Rosettes |
cabbage, carrot, turnip, bluebonnet, kale |
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Vernalization |
A cold treatment (32-45 degrees F for 4-12 weeks) required to trigger or initiate flower formation in biennials |
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Wavelength range of visible light |
400-700 nm |
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light |
radiation in the visible spectrum |
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Quantity of light |
The intensity or amount of light (foot candles) |
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Quality of light |
The wavelength or color of light |
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Duration of light |
Total amount of light energy received. Quantity x # hours of light |
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absorbed light |
when radiant energy is absorbed it is converted primarily to heat energy |
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re-radiation of light |
heat energy converted to radiant energy as long wavelength IR |
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Transmitted light |
when radiant energy passes through an object unaffected |
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Reflected or Scattered light |
when radiant energy is bounced off an object |
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photometer or common light meter |
cheap machine to measure amount of luminance (not very accurate) |
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foot candle |
1 lumen per square foot |
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quantum sensor |
measures actual light intensity or light energy in the visible light range (accurate) |
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transpiration |
evaporation of water from leaves.
Greater light intensity, more transpiration. but too much can cause stomata to close |
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Sun plants |
High optimum light intensity |
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shade plants |
low optimum light intensity |
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photooxidation |
destruction of chlorophyll by high light intensity.
sunburn, leaf turns yellow |
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etiolation |
elongated pale green to yellowish growth due to low light intensity |
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blanching |
lack of color development due to exclusion of light
used on cauliflower, celery, asparagus |
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Practical applications of Auxin |
Fruit set, apical dominance, fruit of flower thinning, herbicide, adventitious root formation (from stem and leaf cuttings or tissue culture) |
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Practical applications of Cytokinin |
Delay leaf aging or abscission, seed germination, adventitious shoot formation (from leaf and root cuttings or tissue culture) |
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Practical applications of Gibberellic Acid (GA) |
Flowering, increase fruit size, overcome bud dormancy, seed germination, sex expression (male) |
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Practical applications of Ethylene |
Fruit ripening, flowering, decreases flower longevity, leaf abscission, leaf epinasty, sex expression (female) |
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Practical applications of Abscisic Acid (ABA) |
Cause dormancy, leaf abscission, close stomata |
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Leaf Epinasty |
Curling and contortion of leaves |
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Leaf Abscission |
Leaf drop |
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Light Acclimatization |
conditioning plants to low light intensity interior environments |
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Methods of light acclimatization |
Grow plants under reduced light intensity for the entire production time OR give final period of greatly reduced light intensity |
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Anthocyanins |
blue, red, and purple pigments |
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Carotenoids |
Orange and yellow pigments, absorb 450-500nm (blue and green) light, can pass energy to chloroplasts to assist in photosynthesis |
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Phytochrome |
Absorbs red light (660nm) and far red light (730nm), involved in photomorphogenic and photoperiodic responses |
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Resting state of phytochrome |
Pr |
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Active form of phytochrome |
Pfr |
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The "Atmospheric Window" |
visible light from the sun passes through the atmosphere relatively unaffected before reaching the earth's surface, whereas other wavelengths are absorbed, reflected or scattered by the atmosphere |
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The "Atmospheric Window" -> Ultraviolet light |
Absorbed by ozone |
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The "Atmospheric Window" -> Infrared light |
Absorbed by carbon dioxide and water vapor in the atmosphere |
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Short-day Plants |
Plants that exhibit their photoperiodic response when the photoperiod is shorter than a critical period photoperiod (need a longer night) |
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Long-day Plants |
Plants that exhibit their photoperiodic response when the photoperiod is longer than a critical period photoperiod (need a shorter night) |
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Photoperiodic responses |
Flowering, growing bulbs, tubers, plantlets, and runners, color development, dormancy, cold acclimatization, stem elongation |
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Photoperiodic responses having to do with dormancy |
color development, dormancy, cold acclimatization |
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Civil twilight |
reflected sky light that occurs approximately 30 minutes before sunrise and 30 minutes after sunset (dawn and dusk) |
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Photoperiod |
The day length a plant perceives, which is one absolute day length plus 1 hour of civil twilight |
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Critical Photoperiod |
Photoperiod above or below which the photoperiodic response is triggered |
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How to stop a short-day plant from flowering in winter |
Add light in the middle of the night |
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How to make a short-day plant flower in summer |
Cover with black cloth to produce an artificial long night |
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How to stop a long day plant from flowering in the summer |
Cover with black cloth to produce an artificial long night |
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How to make a long day plant flower in the winter |
Add light in the middle of the night |
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Chilling requirement
|
The number of hours of cold temperature between 32&45° F required to overcome rest
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