DNA sequencign MS

Question 1

chain termination method:

what is added to the 4 tubes

Answer 1

• single stranded DNA template
• lots of DNA primer
• DNA polymerase
• free nucleotides
• fluorescently-labelled modified nucleotide

Question 2

fluorescently-labelled modified nucleotide

Answer 2

• once its added no more bases can be added after it

Question 3

chain termination method:

PCR

Answer 3

• tubes undergo PCR
• produces many different lengths of DNA as each one terminates at a different point depending on where the modified nucleotide was added

Question 4

chain termination method:

electrophoresis

Answer 4

fragments seperated and visualised under UV light

Question 5

chain termination method:

finding the sequence

Answer 5

• comolmentary base sequence can be read from gel
• the smallest nucleotide is at the bottom, each band after this represents one mroe base added
• by reading the bands from the bottom to the top, you can build up a DNA sequence

Question 6

chain termination method:

sequencing whole organisms

Answer 6

• too long, chop it up
• gneome cut into smaller fragments using restrcition enzymes
• fragments are inserted into bacterial artificial chromosome, man-made plasmids
  
  • each fragment into a different BAC
• the BACs are inserted into different bacteria
• bacreeria divide creating copies
• each piece is sequenced and the pieces are put back in order by computers

Question 7

How has sequences developed

Answer 7

• reliance on computers
• read in parallel