Which process involves adding chemical tags to regulate gene access

The process that involves adding chemical tags to regulate gene access is epigenetic tagging. This refers to a range of modifications, such as the addition of methyl or acetyl groups to DNA or histone proteins, which can influence how tightly or loosely DNA is packaged within the chromatin. When DNA is tightly wound, transcription machinery is less able to access the genes, effectively silencing them. In contrast, more loosely organized chromatin allows for increased accessibility, promoting transcription and gene expression.

Epigenetic modifications are crucial for regulating gene expression without altering the underlying DNA sequence, thus providing a mechanism for how environmental factors can lead to changes in gene activity. This process plays a significant role in development, differentiation, and responses to external stimuli.