Page "Genome" Paragraph 17

When talking about genome composition, one should distinguish between prokaryotes and eukaryotes as the big differences on contents structure they have.

In prokaryotes, most of the genome ( 85-90 %) is non-repetitive DNA, which means coding DNA mainly forms it, while non-coding regions only take a small part.

On the contrary, eukaryotes have the feature of exon-intron organization of protein coding genes ; the variation of repetitive DNA content in eukaryotes is also extremely high.

When refer to mammalians and plants, the major part of genome is composed by repetitive DNA.