Is there any particular pattern among genomes and the organisms who have them?

The answer is none. It has been identified that some less complex organisms have more DNA in their genome that in more complex organisms. Therefore, this indicates that genome size does not really translate to the complexity of an organism / Thos applies especially in eukaryotes. In prokaryotes, there has been shown to be some consistency in the relationship between genome size and a number of genes. This is because prokaryotes rarely have intron regions in their DNA