Recombinant DNA

Question 1

Describe how enzymes could be used to insert the GH gene into a
plasmid.

Answer 1

restriction endoncuelase cuts up DNA
DNA ligase joint dna fragment and GH fragment together

Question 2

Explain the shape of the curve in the figure above of the polymerase chain reaction

Answer 2

initially low because low number of DNA doubling
eventually slows as DNA nucleotides beicne a lining factor

Question 3

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

Answer 3

• add DNA nucleotides, primers, DNA nucleotides, DNA fragment to thermocycler
• heat to 95 degrees to spererate DNA sample
  -cool to 55 degrees so dna nucleotides and primers can anneal
• heat to 72 degrees so dna polymerase( tap ) can catalyse phosophodeuster bonds

Question 4

Suggest two reasons why it was important that the spider gene was
expressed only in the silk glands of the silkworms.

Answer 4

• harmful if produced in other cells
• silk could be harvested

Question 5

Suggest why the plasmids were injected into the eggs of silkworms, rather
than into the silkworms.

Answer 5

• divide into most cells of silk worm
  -so silk glands mor eliekly to have gene

Question 6

Explain why only methods 2 and 3 would produce DNA that E. coli could
use to make HGH.

Answer 6

• contains no introns
• Ecoli cannot splice mRNA

Question 7

The scientists produced a variety of primers for this procedure.

Answer 7

different base sequences complimentary primers required