What is Genetic Engineering?
• The genetic code is universal
• All living things have DNA code
• Each DNA codon codes for the same amino acid, regardless of the species
• Genes transferred from species to species, will produce the same product
• Scientists can cut, copy and paste DNA between species
Genetic Engineering has helped people with
When someone has Type 1 diabetes, their immune system attacks their
own pancreas, which produces insulin.
When someone stops producing insulin, they become very sick, and they
Doctors can give diabetic patients insulin so they can inject insulin in
It used to be hard to get insulin. Scientists had to get it from cows, and
they would only get a little bit.
Scientists found a way to trick bacteria to make
a lot of insulin.
• The genetic code is divided into segments called genes. Each
gene tells our cells how to make a protein. Proteins are the
machines that let our cells function. Insulin is also a protein.
• Scientists took the gene that codes for how to make insulin and
placed it into a bacteria cell.
• The bacteria read the code and started making insulin.
How did they put the DNA into the bacteria?
• Genetic engineers needed to cut DNA at specific places. They did
this with molecules called restriction enzymes. Using the right
restriction enzyme, genetic engineers can cut the DNA wherever
• They use another enzyme called ligase to paste strands of DNA
• Genetic engineers used a type of bacteria called E.coli. They take the
human DNA that codes for how to make insulin, and place it into the
plasmid of the bacteria. (Plasmids are small loops of DNA).
• The bacteria is tricked into making human insulin, and scientists are
able to quickly grow huge vats of E.coli bacteria that make tons of
Genetically engineered food!
• Another example of genetic engineering is BT corn.
• Caterpillars ruin crops, so farmers have to spray insecticide to kill
• Scientists found a naturally occurring bacteria called Bacillus
thuringiensis that produces a protein that’s toxic to the caterpillars.
• Scientists found the gene in the bacteria that codes for the poison
• They put the gene from the bacteria into the DNA of the corn.
• The new corn had corn DNA and bacteria DNA!
How does it work?
1. The Bt gene is transferred from the Bacillus bacteria into the
2. Every cell in the corn plant reads the modified DNA and
makes the protein toxic to caterpillars.
3. The caterpillars feed on the corn plant and swallow the
protein encoded by the Bt gene.
4. The Bt protein (poison) collapses the cells lining the
caterpillar’s gut and the insect dies.