Genetic engineering

What is genetic engineering?

Genetic engineering is the use of technology to change the genetic material of an organism.

Name two examples of uses of genetic engineering.

• Making human insulin from bacteria.

• Making human blood clotting factors in goat’s milk.

• Adding herbicide resistance genes to plants.

• Adding pesticide genes to plants.

Describe two ways to isolate a gene of interest from an organsim’s DNA.

mRNA can be obtained from cells where the gene is being expressed.

Reverse transcriptase can then catalyse the formation of a single strand of complementary DNA (cDNA) using mRNA as a template.

The gene can be synthesised using an automated polynucleotide synthesiser if the nucleotide sequence of the gene is known.

What is a recombinant DNA?

A composite DNA molecule that contains genetic material from two different species.

Describe how enzymes are used in recombinant plasmids.

Restriction enzymes/ endonuclease cuts specific sites either side of the gene of interest and plasmid. The gene of interest can then be inserted into the plasmid using DNA ligase.

Explain why sticky ends are important in combining two sections of DNA

When the same restriction enzyme/ endonuclease has been used to cut the gene of interest and the plasmid, the sticky ends of the gene of interest are complementary to the plasmid’s sticky ends. The sticky ends overlap and can be joined by DNA ligase.