Which term refers to the non-coding regions of DNA that may play roles in gene regulation?

The term that refers to the non-coding regions of DNA is introns. Introns are segments of a gene that are transcribed into precursor mRNA but are removed during the RNA splicing process before translation into protein. While introns do not code for proteins, they are believed to have various roles, including regulating gene expression and allowing for alternative splicing, which can lead to multiple protein variants from a single gene.

In contrast, exons, which are the coding regions, remain in the mature mRNA and are translated into proteins. Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids during protein synthesis, forming an integral part of the coding sequence rather than non-coding regions. Promoters are regions of DNA located upstream of a gene that are crucial for initiating transcription but are not considered non-coding regions in the context of gene regulation roles after transcription.