Genetic Engineering

Genetic Engineering

• Genetic engineering is when you manipulate DNA of an organism to change the phenotype (characteristic) in a certain way.
• A type of cow called Belgian blue has been genetically engineered to have more muscle so that it produces more meat than an average beef cow. A mutation in its genes means that muscle growth doesn't stop when normal cows do. However these cows struggle to give birth and therefore need c sections in order to calf.
• To change a genome the DNA of an organism has to be located isolated, copied and then introduced into a new genome. This changes the phenotype of an organism.
• Genetic engineering allows us to introduce a wider range of traits to an organism.
• Disease resistant organisms can be developed through genetic engineering
• Plants can also be modified in order to withstand pests and diseases as well as the nutritional value of some crops. This increases the farmers yield.

How does it work?

• Stage 1: The desired gene is removed from the donor organism's DNA using enzymes (restriction endonucleases)
• Stage 2: A vector molecule is prepared to carry the DNA into the host cell. A bacterial plasmid is often used as a vector. The bacterial plasmid is opened up using restriction enzymes which leave sticky ends (small sections of DNA that stick out at the end of end required gene). These bacterial plasmids replicate quickly and therefore can increase the number of copies of the gene.
• Stage 3: The new gene is joined into the bacterial plasmid. The sticky ends line up and the new gene is attached using an enzyme called DNA ligases.
• Stage 4: The engineered DNA is incorporated into the bacterium. This is known as transformation. Once the plasmid is inside the host bacterium a new protein will be made.

Advantages

• Better harvests- genetic engineering can create crops that are disease and pest resistant
• Boosts nutrition- genetically engineered crops have a higher level of nutrition
• More desirable traits are guaranteed- genes can be manipulated to have better phenotypes
• It can eliminate diseases

Disadvantages

• Reduces Diversity- undesirable and abnormal traits will be eliminated which limits the diversity of a population.
• Unethical/ Immoral- should we be playing god? Some people feel that humans shouldn't mess with the make up of organisms.
• The effects are unknown- it is a new practise so the long term effects are currently unknown.