Chapter 18, Problem 12TYK

Which of the following statements explains why a larger portion of the DNA in a human cell is transcribed than would be predicted by the 1.5% of the genome that is protein-coding DNA?

1. a. Multiple enhancer regions are being transcribed to amplify the transcription of proteincoding genes.
2. b. Much of this non-protein-coding RNA functions to regulate the translation or degradation of mRNAs.
3. c. Many of these transcriptions produce miRNAs and siRNAs that regulate the transcription of other genes.
4. d. The additional DNA that is transcribed represents introns that are excised from the primary transcript in the production of mRNA.