Term
| Cite the effects of natural auxin on plants that we discussed in class. |
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Definition
| Lateral and adventitious (when a cut allows a root to form) root formation; enhances apical dominance (stimulates top apical bud to grow and lateral buds are suppressed; controls tropic responses (response resulting in curvature toward/away from a stimulus); inhibits fruit and leav abscission (falling off); |
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Term
| Cite the commercial uses of auxin (other than as an herbicide) that we discussed in class. |
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Definition
| Rooting hormone; make plant bushy (by cutting off apical tip); farmers spray plants with auxins to keep the fruits on the plant until they are ready for harvest; auxins used to develop fruits without seeds by completely removing pollin and spraying auxins to encourage ovary to develop into fruit; stimulates fruit development; stimulates root formation in tissue culture; herbicides |
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Term
| Why are synthetic auxins commonly used as herbicides on lawns, golf courses, and other turf areas? |
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Definition
| affect eudicots and not monocots so it affects weeds without hurting grass |
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Term
| Cite the effects of natural cytokinin on plants that we discussed in class. |
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Definition
| Stimulates cytokinesis (cell division); produced in actively growing tissues; works with auxins to control cell division and differentiation; stimulate lateral bud development; delay leaf senescence (programmed death of plant cells/organs) |
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Term
| Cite the commercial uses for cytokinin that we discussed in class. |
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Definition
| stiumlate shoot development in tissue cultures; used to make plants bushy through stimulation of lateral bud development; delay leaf senescence (programmed death of plant cells/organs) |
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Term
| Cite the effects of natural gibberellin on plants that we discussed in class. |
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Definition
| affect stem internode elongation, fruit growth, and seed germination; stimulate cell elongation and division in stems; stimulate production of larger fruits and looser clusters in grapes; stimulate seed germination |
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Term
| Cite the commercial uses of gibberellin that we discussed in class. |
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Definition
| breeding for the mutation with less gibberelin production to make dwarf varieties; adding or breeding for higher levels of gibberelin to stimulate production of larger fruits and looser grape clusters to make larger grapes and reduce fungal pathogens; used in seeds with dormant hormones to break the seeds for germination |
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Term
| Cite the effects of natural abscisic acid on plants that we discussed in class. |
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Definition
| promotes seed dormancy; stimulates stomata to close |
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Term
| Cite the commercial uses of abscisic acid that we discussed in class. |
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Definition
| used to put seeds into a dormant state; anti-transpirants used to stimulate production of abscisic acid which closes stomata for ability to withstand droughts; |
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Term
| Cite the effects of natural ethylene on plants that we discussed in class. |
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Definition
| produced in response to stress and during fruit ripening; communicate with each other through ethylene when environmental attack happens- ethylene is gaseous and is taken in by other plants in the area, possibly allowing an immune response from the other plants for defense; promotes leaf and fruit senescence (death); promotes leaf and fruit abscission (falling off); stimulate fruit ripening |
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Term
| Cite the commercial uses of ethylene that we discussed in class. |
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Definition
| picking unripe fruits/vegetables and shipping, upon arrival they put all into a warehouse and introduce ethylene to stimulate fruit ripening, at least of color; |
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Term
| What mechanisms are used by plants to help them tolerate drought stress? |
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Definition
| reduce transpiration by closing stomata, slow leaf growth, reduce exposed surface area (roll up leaves), grow deeper roots |
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Term
| What mechanism is used by plants to help them tolerate flooding? |
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Definition
| enxymatic destruction of root cortex cells creates air tubes that help plants survive the oxygen deprivation |
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Term
| What mechanisms are used by plants to help them tolerate salt stress? |
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Definition
| producing high concentrations of sucrose that tolerate high concentrations of salt to balance osmosis |
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Term
| What mechanism is used by plants to help them tolerate heat stress? |
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Definition
| increasing production of heat-shock proteins to help protect other proteins from denaturation (breaking apart) due to heat stress |
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Term
| What mechanisms are used by plants to help them tolerate cold stress and / or freezing? |
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Definition
| Cold causes a decrease in membrane fluidity; plants respond by altering lipid composition of membranes to make them more flexible for continued osmosis and increase of sucrose for freezing prevention; |
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Term
| What are the two basic types of defenses used by plants against herbivores / insects? |
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Definition
| physical- thorns, spines, thich cuticle, trichomes; and chemical- distasteful or toxic |
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Term
| Explain how the “hypersensitive response” helps plants defend themselves against pathogens. |
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Definition
| causes cell and tissue death near the infection site, induces production of chemicals that attack the pathogen, stimulates building a cell wall around the pathogen to prevent its spread |
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Term
| Explain how “systemic acquired resistance” helps plants defend themselves against pathogens. |
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Definition
| causes systemic production of defense grenes and is a long-lasting response, salicylic acid is synthesized around the infection site and triggers systemic acquired resistance, then production of defense chemicals occurs throughout the plant like a vaccination |
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Term
| What are the primary metabolites of plants? |
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Definition
| found in all plant cells, necessary for life of the plant: simple sugars, amino acids, nucleotides, fatty acids, and the macromolecules they mak up |
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Term
| What are the three most common classes of secondary metabolites in plants? |
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Definition
| Alkaloids, Terpenoids, Phenolics - branchways off of primary metabolites found in only certain plant species |
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Term
| List 6 basic functions of plant secondary metabolites. |
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Definition
| chemical signals enabling response to environmental cues, defense against herbivores, pathogens, competitors (allelopathy- plant roots produce a chemical that is dispersed into the soil preventing other seeds from germinating there), and UV radiation, aid in pollen & seed despersal (ex: nectar production) |
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Term
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Definition
| chemical signals that help coordinate growth, development, and responses to stimuli; more than one hormone can control a singal metabolic process (ratio of hormones) and one hormone can control many different processes; affect cell division and elongation, control differentiation of cells |
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Term
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Definition
| any response regulating curvature of organs toward or away from a stimulus (light or gravity); positive tropism = towards a stimulus; negative tropism = away from the stimulus |
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Term
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Definition
| regulation of growing direction in response to the sun for photosynthesis; also the auxins navigate to side opposite of sunlight and encourage elongation there, causing bending over |
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Term
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Definition
| regulation of growing direction in response to gravity: shoots are negatively gravitropic and roots are positively gravitropic |
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Term
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Definition
| regulation of growing direction in response to touch; auxins migrate away from where plant is being touched, causing more cell growth there and allowing plants to grow around something |
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Term
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Definition
| hormone responsible for the largest number of plant responses |
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