At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. There was surprise expressed by many that the number of protein-coding sequences in the human genome was much smaller than had been expected. Which of the following could account for most of the rest of the DNA in the human genome?

Question

Quizplus · Accepted Answer

Non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function accounts for most of the rest of the DNA in the human genome. These small RNAs play important roles in regulation of gene expression and other cellular processes. Options A, B, and E are incorrect because they do not account for the functional importance of non-protein-coding DNA. Option C is also incorrect because DNA cannot be translated directly without being transcribed into RNA.

At the Beginning of This Century There Was a General