A2 Biology (OCR)- Sequencing the genome of an organism

Sequencing can only work on DNA lengths of about 750 pairs, which means chromomes must be broken up into sections. Sequencing is carried out a number of times on overlapping fragments, to increase accuracy.

1) Genomes are mapped to identify where they have come from. Info that is already known is used- for example, the location of microsatellites (runs of repetitive sequences of 3-4 base pairs found in the genome).

2) Samples  of the genome are…