Analyze, evaluate, and critique. The human genome consists of coding and noncoding DNA. Research and summarize current investigations into the functions of noncoding DNA.

Nowadays, it is known that approximately 1% of human DNA are protein-coding genes. The other 99% are non-coding DNA. Non-coding DNA genes do not produce proteins. Non-coding DNA consists of certain sequences of vital function to the cells. The main purpose of non-coding DNA is gene activity. A large number of non-coding DNA have a role as regulatory elements. It has the function to inhibit and stimulate certain gene activity and further protein production (transcription factors). Transcription factors bind and/or activate or suppress the process of protein production (transcription). Non-coding DNA is involved in the cutting and splicing of large amounts of DNA. Further, they are involved in transposon reassembly, genome rearrangements and the production of small RNAs.

Non-coding DNA consists of promoters, enhancers, silencers and insulators. Promoters allow binding sites for the proteins. In this way, the transcription is performed. Enhancers provide binding sites for proteins to start the transcription process. They are most commonly placed either before or after the gene they control. Silencers provide binding sites for proteins that inhibit transcription. Insulators provide binding sites for proteins that regulate transcription. They may even block enhancers (enhancer-blocker insulators). The other prevent structural changes in the DNA strand (barrier insulators).

Non-coding DNA may produce specialized RNA molecules such as transfer RNA (tRNAs) and ribosomal RNA (rRNAs), micro RNA (miRNAs). rRNAs and tRNAs aid in organizing protein building blocks (amino acids) into a chain named protein. miRNAs block the process of protein production. Long non-coding RNA (IncRNAs) have diverse functions in gene regulation.

Introns are also non-coding DNA. They are sequences between the exons. Intron messages are spliced by the spliceosome for the production of the coding RNAs (mRNA, rRNA and tRNA).