Consider the following facts about genome composition:

1. Comparing genome compositions helps scientists to understand the evolutionary history of a given genome.
2. Most of the genome (almost 85-90%) in prokaryotes is repetitive DNA.
3. Mammals and plant genomes are made up of repetitive DNA.

Which of the above are true?

Genome composition is used to describe the make up of contents of a haploid genome, which should include genome size, proportions of non-repetitive DNA and repetitive DNA in details. By comparing the genome compositions between genomes, scientists can better understand the evolutionary history of a given genome. 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 referring to mammals and plants, the major part of genome is composed by repetitive DNA.