8.3 Using gnome projects

Question 1

why are prokaryotes genome sequenced

Answer 1

• allows researchers to determine the proteome because there are no introns, regulatory genes or non-coding regions
• can be used in developing treatments e.g. to identify antigen sequences and structures

Question 2

what are the key principles of DNA sequencing

Answer 2

• use restriction enzymes to break DNA into smaller fragments
• use PCR to replicate the fragments
• add in dideoxynucleotides to PCR mixture
• separate fragments of different lengths using gel electrophoresis
• visualise the sequences of bases from the position of fragments

Question 3

what are dideoxynucleotides

Answer 3

act as terminators that prevent further addition of nucleotides to a specific strands