Recombinant DNA technology

Question 1

Define recombinant DNA

Answer 1

DNA that has been formed artificially by combining two or more fragments from different sources

Question 2

What method would you use to amplify a gene of interest?

Answer 2

PCR

Question 3

What enzyme is used to break into a plasmid?

Answer 3

Linearase

Question 4

What is EcoRI and what does it do?

Answer 4

A restriction enzyme
Recognises a 6 bp target site and cleaves DNA to leave ‘sticky ends’

Question 5

What is HaeIII and what does it do?

Answer 5

A restriction enzyme
Recognises a 4 bp target site and cleaves DNA to leave blunt ends

Question 6

What do restriction enzymes leave at the 3’ and 5’ ends?

Answer 6

OH at 3’ end
Phosphate at 5’ end

Question 7

In DNA analysis, what does DNA ligase do?

Answer 7

Forms covalent bonds between two DNA fragments with the same sticky end
It can also join blunt ended fragments, but with less efficiency than sticky ended fragments

Question 8

What 2 enzyme steps are involved in inserting a fragment of DNA into a plasmid?

Answer 8

Digesting with restriction enzyme e.g. EcoRI
Ligating with DNA ligase

Question 9

What 3 requirements must plasmids used as vectors in gene cloning have?

Answer 9

One or more unique restriction enzyme sites.
An origin of replication specific to the host organism.
A selectable marker (usually an antibiotic resistance gene)

Question 10

What do isochizomers do?

Answer 10

Recognise the same site and cut it in the same way

Question 11

What do neoschizomers do?

Answer 11

Recognise the same site but cut it in a different way to each other

Question 12

Define transgenic animal

Answer 12

An animal that has exogenous DNA inserted into its genome