Genetic Engineering and Cloning

• Genetic engineering is the process of modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic
• Plant crops have been genetically engineered to be resistant to diseases or to produce bigger fruits
• bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes
• benefits of genetic engineering:

  • faster and more efficient than selective breeding
  • improves yield and quality
  • can be used for resistance
• risks of genetic engineering:

  • the gene could be transferred to other species
  • more expensive
  • could cause allergic reactions
• genes from chromosomes of organisms can be cut out and transferred to cells of other organisms
• Genetically modified (GM) crops:

  • resistance to insect attack and herbicides
  • generally show increase yields
• concerns about GM crops:

  • effects on population of wild flowers and insects
  • effects of eating them are not fully known
• the process of genetic engineering:

  • enzymes are used to isolate the required gene
  • the gene is inserted into a vector
  • the vector is used to insert the gene into the required cells
  • genes are transferred to the cells of organisms in their early stages of development (so they develop with required characteristics)
• in genetic engineering vectors are usually a bacterial plasmid or virus
• Cloning- tissue culture

  • using a small group of cells from part of a plant to grow identical new plants. this is important for preserving rare plant species and commercially in plant nurseries
• Cloning- cuttings

  an old, simple method used by gardeners to produces many identical new plants from a parent plant
• cloning- embryo transplants

  • split apart cells from a developing animal embryo before they become specialised
  • transplant the identical embryo into host mother
• Adult cell cloning:

  • the nucleus is removed from an unfertilised egg
  • the nucleus from an adult body cell (e.g skin cell) is inserted into the egg cell
  • an electric shock stimulates the egg to divide to form an embryo
  • these embryo cells contain the same genetic information as the adult skin cell
  • when the embryo has developed into a ball of cells, it is inserted into the womb of an adult female to continue its development