a. Less than 2% of the human genome actually encodes proteins meaning it gets converted to mRNA and then translated into protein. The situation is similar for other higher animals and plants. At one time some biologists called this noncoding DNA "junk DNA" when it was first discovered. Today the term "junk DNA" is seldom used. How would you more specifically describe this noncoding DNA and what are some of the categories that it falls into?

b. Bacteria generally have much less noncoding DNA (10% or less) in their genomes than do eukaryotes. Why might bacteria have so little noncoding DNA and higher eukaryotes have so much? (Hint: Consider that bacterial cells can divide very quickly under favorable conditions.)