5.6 - Pest Control Methods

Question 1

Pesticides

Answer 1

• Chemicals that are toxic to pests
• Can cause pests to become resistant to pesticide with overuse
  - Genetic biodiversity gives some pests resistant traits to pesticide
  - Pesticide artificially selects for pests with resistance by killing all the non-resistant individuals, leaving only resistant ones

Question 2

GMOs

Answer 2

• Gene for pest resistant trait is added to the plant through genetic modification
  Example:
• Bt corn with bacteria gene that produces Bt crystals toxic to pests
• Roundup Ready crops are GM to be resistant to broad herbicide (Roundup) meaning roundup will kill weeds, but not crops

Question 3

GMOs and Pesticide Use

Answer 3

• Roundup Ready crops have increased herbicide (glyphosate) use since crops can’t be harmed by it
• Bt corn has decreased insecticide use, since corn makes its own insecticide (Bt crystals)

Question 4

GMOs and Genetic Diversity

Answer 4

• GM crops are all genetically identical (clones) so there is no genetic diversity in the pop.
• If there is disease or pest that does affect the GM crops, they’re all vulnerable and there’s no chance of a genetic mutation providing an adaptive trait