Genetic Engineering

Genetic Engineering

1. Uses Enzymes to Cut and Paste Genes

   • Basic idea is to copy a useful gene from one organism's chromosome into the cells of another...
     • 1) Useful gene is ''cut'' from one organism's chromosome using enzymes
       • EcoR1
     • 2) Enzymes are then used to cut another organism's chromosome and the insert the useful gene
       • ''Glued'' together by Ligase
     • 3) Scientists use this method to do all sorts of things
       • For example, the human insulin gene can be inserted into bacteria to produce human insulin

2. Genes can be Transferred into Animals and Plants

   • The same method can be used to transfer useful genes into animals and plants at the very early stages of their development
     • This means they'll develop useful characteristics:
       • 1) Genetically Modified (GM) crops have had their genes modified
         • e.g. to make them resistant to viruses, insects or herbicides
       • 2) Sheep have been genetically engineered to produce substances, like drugs, in their milk that can treat human diseases
       • 3) Genetic disorders like cystic fibrosis are caused by faulty genes.
         • Scientists are trying to treat these disorders by inserting working genes into suffers. this is called gene therapy.

3. Controversial Topic

   • It is an exciting new area in science which has the potential for solving many of our problems (e.g. treating diseases, more efficient food production etc.) but not everyone thinks it's a great idea.
   • There are worries about long-term effects of genetic engineering - that changing a person's genes might accidentally create unplanned problems, which could then be passed on to future generations.

4. It's the same as GM Crops - There Are Pros and Cons

   • 1) Some people say that growing GM crops will affect number of weeds and flowers (and so the population of insects) that live in and around the crops - reducing farmland biodiversity
   • 2) Not everyone is convinced that GM crops are safe. People are worried they may develop allergies to the food - although there's probably no risk for this than for eating usual foods.
   • 3) A big concern is that transplanted genes may get out into the natural environment
     • For example, the herbicide resistance gene may get picked up by weeds, creating a new 'superweed' variety
   • 4) On the plus side GM crops can increase yield of crop, making more food.
   • 5) People living in developing nations often lack nutrients in their diet. GM crops could be engineered to contain the nutrient that's missing.
     • For example, they're testing 'golden rice' that contains beta-carotene - lack of this substance can cause blindness
   • 6) GM crops are already being grown elsewhere in the world (not in UK) often without any problems