Friday, March 8, 2013

Genetically modified maize - Wikipedia, the free encyclopedia

Genetically modified maize - Wikipedia, the free encyclopedia: It is anticipated resistance to Bt will evolve in the form of a recessive allele in the pest. Because of this, a pest that gains resistance will have an incredibly higher fitness than the wild type pest in the Bt corn fields. If the resistant pest is feeding in the non-Bt corn nearby, the resistance is neutral and offers no advantage to the pest over any nonresistant pest. Ensuring there are at least some breeding pests nearby that are not resistant increases the chance the resistant pests will choose to mate with nonresistant ones. Since the gene is recessive, all offspring will be heterozygous, and the offspring from that mating will not be resistant to Bt and therefore no longer a threat. Using this method, scientists and farmers hope to keep the number of resistant genes very low, and use genetic drift to ensure any resistance that does emerge does not spread.

The pests are an R chaotic feeder on V plants, when they are attacked too much by Oy pesticides then they mutate into varieties that are secretive and deceptive to this pesticide, i.e. not hurt by it because the pesticide no longer targets them. By keeping this Oy attack low it is like fewer Oy predators such as hyena chasing R gazelles, they select less for faster gazelles that will outrun Oy predators later. These innovations against pesticides can build resistance, this is when pests cooperate with each other to transfer this immunity often by direct genes transferred between them to nonresistive pests. This is similar to political problems in a Roy country, Oy secret police target R terrorists and freedom fighters until they kill off those vulnerable leaving others smart enough to evade the secret police. They then transfer this knowledge to Ro demonstrators who can have a united front against the Oy forces. When left alone this Ro resistance can weaken until they let their guard down and become vulnerable to attack as with the pests.

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