In my Musing this week I mention the little worm C. elegans, beloved by developmental biologists. The worm has only 959 cells, yet it is a fairly sophisticated creature.
You can find the complete parts list here. In every one of C. elegans's 959 cells there are identical copies of DNA, carried on six chromosomes, something like 18,000 genes, coded as 100 million paired chemical units of just four kinds along the DNA double helix. If you are interested in the details, or just want to see how much biologists have learned about this little creature, you can find it all on the web.