During DNA replication,
A) all methylation of the DNA is lost at the first round of replication.
B) DNA polymerase is blocked by methyl groups, and methylated regions of the genome are therefore left uncopied.
C) methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication.
D) methylation of the DNA is maintained because DNA polymerase directly incorporates methylated nucleotides into the new strand opposite any methylated nucleotides in the template.
E) methylated DNA is copied in the cytoplasm, and unmethylated DNA is copied in the nucleus.

Question

Quizplus · Accepted Answer

Methylation of DNA is maintained during replication through the action of maintenance methyltransferases, which recognize hemimethylated CpG sites (where only one strand is methylated) and add a methyl group to the newly synthesized strand. This ensures that the methylation pattern is faithfully transmitted to daughter cells.

During DNA Replication