Lecture 20 - Lecture 20 Land Use Urbaniza3on A er this...

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Lecture’20’ Land’Use’&’Urbaniza3on’
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Announcements: Exam’3’next’week’Tuesday;’Review’Session’Next’ Monday’5-7’pm’314’ Altgeld’Hall’ Environmental’Issues’Presenta±on’due’Nov’14 th’ Waste’&’Recycling:’Extra’credit’online’ac±vity’due’at’the’ end’of’Thanksgiving’Break’ A+er this class you should be able to explain: Examples of beneFts and drawbacks of using transgenic organisms with respect to key environmental problems ±our key aspects of human land-use needs The history of urban development in the US Key environmental problems created by many modern US ciAes Key principles that can be implemented in Urban Planning to turn ciAes from being causes of environmental problems into soluAons
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Bacillus thuringiensis ’( Bt)’is’a’soil’ bacterium’that’makes’toxins’that’are’ lethal’to’many’insects.’Despite’being’ highly’toxic’to’insects,’it’has’a’short’ residence’3me,’and’breaks’apart’into’ non-toxic’cons3tuents.’Because’of’these’ proper3es’and’its’“natural”’origin,’it’is’ one’of’the’few’insec3cides’that’is’ permi\ed’for’use’in’cer3Fed’organic’ food’produc3on.’ The gene that produces the toxin has now been moved into so-called “Bt strains”, primarily of corn. These plants now produce the toxin in their own tissues, making them resistant to a wide variety of insect attack without the need to apply insecticides. BT strain “wild” strain Bt toxin crystals Main’applica3ons’of’transgenic’organisms’ in’agriculture:’ Insect control Environmental Benefts: Reduced’reliance’on’pes3cides’
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ScienceDaily (Feb. 7, 2008) A’pest’insect’known’as’bollworm’ is’the’frst’to’evolve’resistance’in’ the’feld’to’plants’modifed’to’ produce’an’insec3cide’called’ Bt,’ according’to’a’new’research’ report.’ First Documented Case Of Pest Resistance To Biotech CoGon (A)Pes3cide’resistance’will’evolve’Faster’in’pests’ Feeding’on’transgenic’ Bt’crop’strains’ (B)Pes3cide’resistance’will’evolve’Faster’in’pests’ with’tradi3onal’pes3cide’applica3on’ trhough’ spraying’ (C)No’way’to’predict’
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How’might’you’prevent’the’evolu3on’of’pes3cide’ resistance’when’using’BT’strains’of’crop’plants?’ Bt strain Non-Bt refuge When’transgenic’crop’strains’ such’as’ Bt’corn’are’used’that’ “make’their’own’pes3cide”,’it’ is’now’mandated’by’federal’ law’that’a’farmer’has’to’plant’ non-Bt’refuges,’so’that’non- resistant’varie3es’of’crop’pests’ can’con3nue’to’Fnd’food’and’ flourish’and’interbreed’with’ resistant’strains’of’pests,’thus’ limi3ng’their’propor3on’in’the’ overall’popula3on.’
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Lecture 20 - Lecture 20 Land Use Urbaniza3on A er this...

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