Final answer:
The statement is true; DNA methylation can impact transcriptional activity by affecting gene expression levels through epigenetic regulation. Increased methylation leads to tighter DNA coiling and reduced transcription, whereas decreased methylation allows greater DNA accessibility for transcription.
Step-by-step explanation:
The statement is true; levels of methylation can indeed impact the transcriptional activity of the DNA. In the context of epigenetic regulation, DNA methylation typically results in lower levels of gene expression.
This is because highly methylated DNA regions, particularly when paired with deacetylated histones, tend to be more tightly coiled and thus transcriptionally inactive. Conversely, decreased DNA methylation and chemical modification of histone tails, such as acetylation, can lead to more loosely packed DNA that is available for transcription.
These modifications are a response to environmental factors, like UV rays, which can alter the accessibility of DNA for transcriptional machinery and influence gene expression patterns across multiple generations.
It is important to understand that the effects of DNA methylation are part of a wider network of epigenetic mechanisms that impact not just the transcriptional level, but also the epigenetic, transcriptional, and translational levels of gene expression.