Genetic Modification (genetic engineering)

describe the role of restriction enzymes

• they cut DNA at specific sites leaving ‘sticky ends’

describe the role of ligase enzymes

• they join pieces of DNA together and seal the ‘sticky ends’

describe the process of genetic engineering (human insulin production)

1. Restriction enzyme cuts out the human insulin gene and cuts open the vector DNA.

2. Vector DNA and insulin gene DNA are mixed with ligase enzymes.

3. Ligases join the DNA fragments, forming recombinant DNA.

4. Recombinant DNA is inserted into host cells.

5. Transgenic bacteria now produce human insulin protein from the inserted gene.

describe vectors

• something used to transfer DNA into a cell

describe the different types of vectors

• plasmids - small, circular molecules of DNA that are transferred between bacteria

• viruses - insert DNA into organisms they infect

describe how GM plants improve food production

• making them resistant to insects - farmers don’t have to spray as many pesticides - crop yield increased

• making them resistant to herbicides - farmers can spray their crops to kill weeds without affecting the crop - crop yield increased

define the term transgenic

• the transfer of genetic material from one species to a different species