Final answer:
DNA sequences that regulate a nearby gene on the same chromosome are called cis-acting regulatory elements, which include enhancers and repressor sequences that bind transcription factors to control gene expression.
Step-by-step explanation:
DNA sequences that exert their effects only over a particular gene on the same chromosome are called cis-acting regulatory elements. In eukaryotes, these elements can range in location from being very close to a gene's promoter region to being quite far away. An important function of cis-acting elements is to control gene expression by serving as binding sites for transcription factors.
For example, enhancers are types of cis-acting elements that can increase the rate of transcription of a gene when transcription factors bind to them, even though they might be located thousands of nucleotides away from the gene they regulate. On the other side, repressor sequences can bind repressors and can act to downregulate gene expression.
Cis-acting elements are essential for the precise regulation of gene expression during various biological processes, including development, response to environmental stimuli, and maintenance of cell-specific functions.