AP BIOLOGY

Detailed explanation-1: -Methyl tags most often silence genes, or keep them turned off.-Methyl tags recruit proteins that bind to methylated DNA, which then blocks transcription machinery from binding. Histones are proteins that help organize DNA.

Detailed explanation-2: -Tumour suppressor genes (TSGs) inhibiting normal cellular growth are frequently silenced epigenetically in cancer. DNA methylation is commonly associated with TSG silencing, yet mutations in the DNA methylation initiation and recognition machinery in carcinogenesis are unknown.

Detailed explanation-3: -Our study shows that dexamethasone inducibility can be useful to silence vital genes in transgenic roots.

Detailed explanation-4: -Abstract. A large body of evidence demonstrates that DNA methylation plays a role in gene regulation in animal cells. Not only is there a correlation between gene transcription and undermethylation, but also transfection experiments clearly show that the presence of methyl moieties inhibits gene expression in vivo.