I notice WK that Faith has joined in here. Her comment about "over my head" is a valid one.
This is supposed to be a "beginner's guide". This post and a preceding one are not particularly useful to a beginner. Can we try to keep the material at a much clearer level.
It would be nice if this thread did not assume any previous knowledge.
You may write:
DNA methylation is when the Cytosine of CpG doublets become methylated, either spontaneously or due to the action of a methyltransferase enzyme.
But one reads:
"DNA something strange sounding is when something else
really strange sounding happpens, either spontaneously or due to the action of abracadabra chemical term."