Question

"to which nucleotide base are methyl groups added during the process of dna methylation?"

Answer 1

Methylation occurs on cytosine and adenine nucleotide bases. Methylation of Cytosine occurs with a high affinity, especially in the CpG islands. Methylation happens at the 5’ carbon in the pyrimidine ring to form methyl-cytosine through the addition of a methyl group.