3.8.4.1 Recombinant DNA technology

Question 1

What does recombinant DNA technology involve

Answer 1

Transfer of DNA fragments between organisms due to the universal genetic code and transcription translation mechanisms

Question 2

What are the three methods of producing DNA fragments

Answer 2

Reverse transcriptase from mRNA restriction enzymes to cut DNA gene machine to synthesise

Question 3

What enzyme converts mRNA into cDNA

Answer 3

Reverse transcriptase

Question 4

What enzyme cuts DNA into fragments

Answer 4

Restriction endonuclease

Question 5

How does a gene machine create DNA fragments

Answer 5

Synthesises DNA sequences based on known base sequences

Question 6

What are the two methods of amplifying DNA fragments

Answer 6

In vitro PCR and in vivo culturing transformed host cells

Question 7

What is the in vitro method for DNA amplification

Answer 7

Polymerase Chain Reaction PCR

Question 8

What is the in vivo method for DNA amplification

Answer 8

Culturing transformed host cells

Question 9

Why are promoter and terminator regions added to DNA fragments

Answer 9

Ensure correct transcription and translation in host cells

Question 10

What is the role of restriction enzymes and ligases in recombinant DNA

Answer 10

Restriction enzymes cut DNA ligases join DNA into vectors

Question 11

How are host cells transformed with recombinant DNA

Answer 11

By inserting vectors containing the DNA fragment

Question 12

How can genetically modified GM cells be detected

Answer 12

Using marker genes in the recombinant DNA

Question 13

Why are marker genes used

Answer 13

To identify cells that have successfully taken up the recombinant DNA

Question 14

What are the ethical considerations of recombinant DNA technology

Answer 14

Balancing humanitarian benefits against environmentalist and anti-globalisation concerns

Question 15

How is recombinant DNA technology related to gene therapy

Answer 15

It allows insertion of functional genes to treat genetic disorders

Question 16

What are the ethical issues of recombinant DNA in agriculture industry and medicine

Answer 16

Concerns over unnatural modifications animal welfare and human safety

Question 17

What are the financial issues of recombinant DNA in agriculture industry and medicine

Answer 17

High development costs patenting by companies creating monopolies

Question 18

What are the social issues of recombinant DNA in agriculture industry and medicine

Answer 18

Access inequality reliance on biotech companies potential for job losses

Question 19

Describe the role of Restriction endonuclease

Answer 19

cut plasmid/vector;

Question 20

Describe the role of ligase

Answer 20

joins gene/DNA to plasmid/vector;

Question 21

Suggest two features of the structure of different proteins that enable them
to be separated by gel electrophoresis.

Answer 21

1. Mass/number of amino acids/polypeptides;

Accept weight for mass
Ignore density/size
Accept length of polypeptide/amino acid chain
Accept primary structure /sequence of amino acids.
Accept tertiary structure

2. Charge;
3. R groups (differ);

Question 22

Describe and explain how the polymerase chain reaction (PCR) is used to
amplify a DNA fragment.

Answer 22

1. (Requires DNA fragment) DNA polymerase, (DNA) nucleotides and
   primers;
2. Heat to 95 °C to break hydrogen bonds (and separate strands);
   Accept temperature in range 90 to 95 °C.
3. Reduce temperature so primers bind to DNA/strands;
   Accept temperature in range 40 to 65 °C.
4. Increase temperature, DNA polymerase joins nucleotides (and repeat
   method);
   Accept Taq polymerase for DNA polymerase.
   Accept temperature in range 70 to 75 °C.