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Chemical tags on DNA control whether specific genes are switched on or off. The figure is taken from Smithsonian, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Epigenetics alters gene activity without changing DNA code

Chemical tags on DNA control whether specific genes are switched on or off

Epigenetics refers to heritable changes in gene expression that occur without altering the underlying DNA sequence. Environmental factors like diet, stress, and toxin exposure trigger chemical modifications such as DNA methylation or histone acetylation. These chemical tags modify chromatin structure, dictating whether cellular machinery can access and read target genes.

Identical twins lg — National Human Genome Research Institute · Public domain · source

Where this comes from

Smithsonian

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Tags: biology, epigenetics, genetics

Epigenetics alters gene activity without changing DNA code: the short answers

Where does this come from, and can I check it?: Chemical tags on DNA control whether specific genes are switched on or off. The figure is taken from Smithsonian, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a science fact?: Yes. It sits on the Science shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.