Ocr A2 Biology - Genetic Engineering

Front 1

What is genetic engineering?

Back 1

Genetic engineering is the manipulation of an organism's DNA.

Front 2

Organisms that have had their DNA altered are called...

Back 2

...transformed organisms/genetically modified organisms.

Front 3

What is the name of DNA from transformed organisms and how is it formed?

Back 3

• DNA from transformed organisms care called recombinant DNA.
  
• Recombinant DNA is formed by joining DNA from different sources.

Front 4

Explain, using basic terminology, how genetic engineering works.

Back 4

Extracting a gene from one organism and inserting it into another organism (often a different species).

Front 5

Genes can also be .......... instead of extracted from an organism.

Back 5

manufactured

Front 6

An organism that has been genetically modified to include a gene from a different species is called a...

Back 6

...transgenic organism.

Front 7

[Genetic Engineering] How is the desired gene extracted?

Back 7

Using restriction enzymes

Front 8

[Genetic Engineering] State how the desired gene is inserted into an organism. Mention the enzymes involved.

Back 8

The isolated desired gene is inserted into a vector using restriction enzymes and DNA ligase.

Front 9

[Genetic Engineering #1] What is the first step of genetic engineering.

Back 9

• The DNA fragment is inserted into vector DNA.

Front 10

What is a vector? Give two examples.

Back 10

• A vector is something that is used to transfer DNA into a cell.
• They can be plasmids (small, circular molecules of DNA in bacteria) or bacteriophages (viruses that infect DNA).
  

Front 11

[Genetic Engineering #2] Explain the second step of genetic engineering.

Back 11

• The vector DNA is cut open using the same restriction enzyme that was used to isolate the DNA fragment containing the desired gene.
• This results in the sticky ends of the vector being complementary to the sticky ends of the desired gene.

Front 12

[Genetic Engineering #3] What is the final step in genetic engineering? What is the name of this process?

Back 12

• The vector DNA and DNA fragment are mixed together with DNA ligase.
• DNA ligase joins up the sugar-phosphate backbones of the two bits.
• This process is called ligation.

Front 13

The new combination of bases in the DNA (DNA vector + DNA fragment) is called...

Back 13

...recombinant DNA.

Front 14

The vector needs to be transferred into the bacterial cells. State the two forms the vector could be in to be inserted into the bacterium.

Back 14

• A plasmid
• A bacteriophages

Front 15

If a plasmid vector is used, the bacterial cells have to be .......... to take in the plasmid vector and its DNA. Explain how this is done and the name of the process.

Back 15

• persuaded
  
  
• A suspension of bacterial cells is mixed with the plasmid vector in a machine called an electroporator.
• This machine is switched on and an electrical field is created in the mixture, which increases the permeability of the bacterial cell membranes.
• This allows them to take in the plasmids.
• This is called electroporation.

Front 16

Explain how a bacteriophage vector is transferred to a bacterium.

Back 16

• A bacteriophage vector (a virus with the desired gene in its DNA) will infect the bacterium by injected its DNA into it.
• The phage DNA (with the desired gene) then integrates into the bacterial DNA.