Regulatory sequences are specific regions of DNA that control the expression of genes. They act like switches, turning genes on or off in response to various signals. These sequences can be found near the genes they regulate or even far away, influencing when and how much a gene is expressed. These sequences include elements such as promoters, enhancers, and silencers. Promoters are located at the start of a gene and are essential for initiating transcription, while enhancers can boost gene expression from a distance. Silencers, on the other hand, can inhibit gene expression, providing a complex layer of control in cellular functions.