By turning genes on and off, methyls can have a profound impact on the form and function of cells and organisms, without changing the underlying DNA.
通过开启和关闭基因，甲基不改变基本的DNA链就可以对细胞和机体的形态与机能产生深远的影响。
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Methyls, small chemical groups within cells, latch on to certain areas along the DNA strand. The methyls serve as a kind of switch that renders genes active or inactive.