Biology - Genetic Engineering

Def: the artificial manipulation or alteration of genes.

AKA: Genetic manipulation, genetic modification, recombinant DNA technology, genetic splicing & gene cloning

• Human genes inserted into bacteria
• Bacterial genes inserted into plants
• Human genes inserted into other animals

• A source of DNA – Foreign DNA, from an organism
• A cloning vector – accepts DNA and replicates it eg. Bacterial plasmid
• Restriction Enzyme – cuts DNA in specific places, acts like a genetic scissors
• DNA Ligase – ‘glue’ foreign DNA to join with the DNA of the cloning vector

• Restriction Enzymes
• Only cut DNA at particular sites (restriction site)
• If DNA from 2 different organisms is cut with the same restriction enzyme, the cut ends from both sources will be complimentary

• DNA Ligase
• Enzyme that sticks DNA molecules from different sources firmly together
• Will only work if both DNA have been cut by the same restriction enzyme

• 1. Isolation
• Removal of both human DNA containing target
• gene from its chromosome and plasmid DNA from bacterium

• 2.Cutting
• Human DNA and plasmid DNA are cut using the restriction enzyme at recognition site

• 3. Ligation
• Target gene is placed into the DNA of the
• plasmid or cloning vector and joins (glues) onto it using DNA Ligase

• 4.Transformation
• This is the uptake of DNA into a cell. Only about 1% of bacterial cells take up plasmid and target gene.

• 5. Cloning
• Identical copies of the bacterium are produced using a nutrient medium

• 6. Expression
• Getting the organism with the recombinant DNA to
• produce the desired product

Plant: Bacterial genes are added to crop plants so they will have resistance to herbicides

Animal: Some people can’t reproduce a protective protein (ATT) in their lungs leading to collapse of alveoli, a condition known as emphysema. ATT is inserted into sheep DNA and sheep produce the protein in their milk.

• Micro-organism: Human insulin is inserted into bacterium which reproduces large quantities of insulin
• used by diabetics

• Fear that animals will suffer
• Fear that humans may be genetically modified
• Use of GMOs as a food source