Genetic engineering

• what is genetic engineering?

  • modification of the genome of an organism by the insertion of a desired gene from another organism - genes from chromosomes of humans and other organisms can be cut out and transferred to cells other organisms
  • enables the formation of an organism with beneficial characteristics
• what is a use for genetically modified bacteria cells?

  produce human insulin to treat type 1 diabetes
• describe the effects of genetic engineering

  • increased crop yields for growing population
  • useful in medicine possibly to overcome some inherited disorders
  • GM crops produce scarce resources (golden rice produces beta-carotene (source of VA in body)
• Risk of genetic engineering

  • long-term effects of consumption of GM crops unknown
  • negative environmental impacts
  • late-onset health problems in GM animals
  • GM seeds are expensive, LEDC may be unable to afford or may become dependent on businesses that sell them
• what is bacillus thuringiensis (Bt)?

  • insect larvae are harmful to crops
  • bacterium which secretes a toxin that kills insect larvae
• how is genetic engineering used to protect crops against insects?

  • gene for toxin production in Bt can be isolated and inserted into the DNA of crops
  • Bt crops now secrete toxin which kills any insect larvae that feed on it
• benefits of Bt crops

  • increased crop yields
  • lessens need for artificial insecticides
  • Bt toxin is specific to certain insect larvae so is not harmful to other organisms that ingest it
• risks of Bt crops

  • long term effects of consumption unknown
  • insect larvae may become resistant to toxin
  • killing reduces biodiversity
• describe the process of genetic engineering

  1. DNA is cut at specific base sequences by restriction enzymes to create sticky ends
  2. vector DNA cut using the same restriction enzymes to create complementary sticky ends
  3. ligase enzymes join the sticky ends of the DNA and vector DNA forming recombinant DNA
  4. recombinant DNA mixed with and taken up by target cells
• what is a vector?

  structure that delivers the desired gene into the recipient cell