Think about it:
- strings of bytes organized into tracks
- non-sequential ordering of sectors within tracks (basically the disk spins until it picks up the right sequence identifying the start of a sector)
- autosyncing bytes
- the D5 AA 96 and D5 AA AD prologue marker and DE AA EB epilogue marker
- data that can be ignored before the prologue and after the epilogue
- transcribing the bytes on disk to data bytes (the 5-and-3 and 6-and-2 encodings)
- those data bytes in many cases coding for particular BASIC tokens
It's far from a perfect analogy, but some of it has the same flavour as genetic structure.