Genetic modification (genetic engineering)

• What is genetic modification (engineering)  

  Changing an organism’s genetic material by removing, changing or inserting individual genes to give it new characteristics 
• What are genetically modified species known as? (2 names)

  Genetically modified organisms (GFOs) or transgenic organisms
• What are the two types of enzymes required for GM

  Restriction enzymes

  ligase enzymes
• genetic Modification Process

  • Identify the DNA (gene) (coding for whatever needs to be produced) needing to be inserted
  • Cut out gene from a human chromosome using restriction enzymes (Enzyme scissors)
  • will form sticky (/complementary) ends 
  • A small ring of DNA called a plasmid is cut using the same restriction enzyme
  • The human gene is inserted into this plasmid 
  • DNA ligase (enzyme glue) is used to join the human gene with the plasmid
  • The genetically engineered bacteria can be placed in a fermenter to quickly reproduce in controlled conditions+make large quantities of the human protein 
• What is recombinant DNA


  Recombinant DNA is DNA taken from two different organisms combined into one strand.
• What is the role of plasmids and viruses in genetic modification?


  Plasmids and viruses help move DNA between cells. Plasmids work in bacteria and yeast, while viruses work in human cells or bacteria.
• Define the term vector in genetic modification.


  A vector takes up pieces of recombinant DNAand then inserts this DNA into other cells.
• How do plasmids and viruses transfer DNA?

  They carry DNA into cells. 

  Plasmids carry DNA into bacteria or yeast by passing into the cell through the cell membrane. 

  Viruses carry DNA into human cells or bacteria. Viruses can inject DNA through the membrane into bacterial the cell without entering the cell itself.
• How do bacteria reproduce recombinant plasmids?


  Bacteria make copies of the modified recombinant DNA inside them as they reproduce by asexual reproduction. This passes on the recombinant DNA to their offspring.
• Why are genetically engineered bacteria useful in the production of specific proteins e.g. insulin?

  Once bacteria have been genetically modified to contain the correct gene, they are able to reproduce quickly and synthesise large quantities of the specific protein required.
• What method is used to mass produce insulin from genetically modified bacteria?


  In order to mass produce insulin from genetically modified bacteria the bacteria are grown in fermenters and the insulin product is extracted and purified.
• Why is an industrial fermenter used to produce human insulin in large quantities?

  The conditions inside a fermenter can be regulated to ensure optimum growth conditions for the bacteria. This will maximise the yield of insulin that is collected.
• What are GM crops?


  GM crops, or genetically modified crops, are crop plants that have been genetically altered with DNA from another organismto possess certain desirable traits, such as insect resistance.
• purpose of modifying crop plants to be herbicide-resistant?

  Modifying crop plants to be herbicide-resistant ensures that when herbicide is used, only weeds are killed, not the crop plants.
• What is a benefit of genetically modified crops to the farmer?

  Growing genetically modified crops may have many benefits to the farmer including:

  • Increased crop yield.
  • Decreased costs.
  • Reduction in the requirement for pesticides, herbicides or fertilisers.
• definition of a 'transgenic organism'?

  A transgenic organism contains DNA from more than one species due to genetic modification.
• transgenic- species 


  Transgenic means the transfer of genetic material from one species to a different species.
• Why bacteria useful for GM purposes: genetic code

  Contain the same genetic code as organism we are taking genes from, meaning they can produce the same proteins 
• Why crop plants, eg wheat and maize, have been GM: pests

  To contain a gene from a bacterium that produces a position killing insects, making them resistant to insect pests (eg caterpillars) which improves crop yield as less crops will die
• Why some crop plants have been GM: vitamins

  To produce additional vitamins and improved nutritional value, improving crop health and life
• Why some crop plants have been GM: drought 

  To be drought-resistant (grow better in very dry conditions), improving crop yield as less crops will die
• GM meaning to reference of DNA sequences 

  Refers to manipulation of DNA sequences of an organism
• In GM, what is the altered DNA called 

  Recombinant DNA (rDNA)
• What is a transgenic organism 

  An organism containing DNA from a different species