Fill in the blanks to describe how bacterial vectors are used to genetically modify plants:

A small circular piece of DNA called a plasmid is extracted from the bacteria Agrobacterium tumefaciens.

A restriction enzyme is used to cut the plasmid and this removes a tumour forming gene.

A gene for disease resistance is located in another organism and cut using the same restriction endonuclease enzyme.

sticky ends are created by using the same enzyme to cut the gene and the plasmid and so the gene connects into the enzyme by the pairing of complementary base pairs and the action of the enzyme DNA ligase .

The plasmid is inserted back into the bacterial cell .

The bacteria is inserted into the plant cell .

The gene from the plasmid inserts into the plant chromosome, this makes the plant cells transgenic .

For each of the three case studies below, decide if the organisms involved are transgenic or genetically modified.

Soya beans have a huge range of applications and need to be grown in large numbers. Herbicides are used to kill weeds but can damage the plants. A gene from another species has been introduced into the Soya bean genome to make them resistant to the herbicide used to kill their competitors.

Bt tomatoes have had a gene from the bacterium Bacillus thuringiensis incorporated into the tomato genome. The gene gives the tomato the ability to produce its own insecticide protein in the leaves so farmers don’t have to spray the crop. The insecticide is not produced in the fruits grown for consumption.

Antisense tomatoes contained another copy of their gene for polygalacturonase enzyme but a complementary version introduced by a bacterial vector. The second copy of the gene meant that mRNA produced from it was complementary to that of the gene and instead of being translated the mRNA paired up preventing the enzymes production.

Transgenic Transgenic Genetically modified

Give four ways new genes can be introduced into plant cells:

The gene gun shoots genes adhered to gold spheres into the plant cell.

Use of the bacterial vector Agrobacterium tumefaciens.

Electroporation used to make cell membranes more likely to take up genes.

Microinjection of the gene into the cell.