genetic engineering

• What does genetic engineering involve? Use

  Genetic engineering involves modifying an organism's genome to introduce desirable characteristics. This involves the use of enzymes and vectors (carriers).
• What are restriction enzymes? 2

  Restriction enzymes recognize specific sequences of DNA and cut the DNA at those points.

  The piece of DNA are left with sticky ends where they have been cut.
• What are ligase enzymes?

  Ligase enzymes are used to join two pieces of DNA together at their sticky ends.
• What is recombinant DNA?


  Two difference bits of DNA stuck together are known as recombinant DNA.
• What is a vector?

  A vector is something that is used to transfer DNA into a cell.
• What are the two types of vectors called?

  There are two types of vector.

  Plasmids and Viruses
• Describe plasmid vectors.


  Plasmids are small, circular molecules of DNA that can be transferred between bacteria.
• Describe viruses.


  Viruses insert DNA into the organism they infect.
• HOW GENETIC ENGINEERING WORKS. 1

  The DNA you want to insert is cut out with a restriction enzyme.
• HOW GENETIC ENGINEERING WORKS.2

  The vector DNA is then cut open using the same restriction enzyme.
• HOW GENETIC ENGINEERING WORKS. 3

  The vector DNA and the DNA you are inserting are left with sticky ends. They are mixed together with ligase enzymes.
• HOW GENETIC ENGINEERING WORKS. 4

  The ligases join the pieces of DNA together to make recombinant DNA.
• HOW GENETIC ENGINEERING WORKS. 5

  The recombinant DNA is inserted into other cells.
• FINALLY, HOW GENETIC ENGINEERING WORKS. 6


  These cells can now use the gene you inserted to make the protein you want.
• Genetic engineering is useful. How is genetic engineering useful in agriculture?

  In agriculture, crops can be genetically modified to be resistant to herbicides. Making crops herbicide-resistant means farmers can spray their crops to kill weeds, without affecting the crop itself. This can also increase crop yield.
• How is genetic engineering useful in medicine?

  In medicine, as well as genetically engineering bacteria to produce human insulin, researchers have managed to transfer human genes that produce useful proteins into sheep and cows. These proteins can then be extracted from the animal.
• However, there are concern about genetic engineering of animals. Why? 2

  There are concerns about the genetic engineering of animals. It can be hard to predict what effect modifying its genome will have in the organism- many genetically modified embryos do not survive and some genetically modified animals suffer from health problems later in life.
• Another concern about genetic modified crops. Why? 2

  There are also concerns about genetically modified crops. One is that transplanted genes may get out into the environment. For example herbicide resistance gene may be picked up by weeds, creating a new 'superweed' variety.

  
  

  Another concern is that genetically modified crops could adversely affect food chains- or even human health.