The human genome contains less than 2% coding _SPAN_PURPLE exons
within _FIG_ch17/RNA_splicing.html genes.
The remaining DNA consist of:
- _SPAN_VIOLET introns and regulatory sequences
such as _FIG_ch18/activator.html enhancers
- _SPAN_BGREEN unique noncoding DNA
contains many pseudogenes (genes that have accumulated mutations and became nonfunctional)
- _SPAN_DGREEN repetitive DNA
are sequences that are repeated many times; much of these are
_SPAN_GREEN transposable elements
that can "jump" between chromosomes, leading to _SIZ_transposition.html transpositions.