Chromosomes (DNA, really) don't appear to be the entire story. For instance, how does an embryo made of cells, each holding DNA identical to the others develop into a complex organism? On top of that, why do skin cells taken from frog embryos not turn into simply skin? (they turn into something dubbed ‘xenobots’, intro here, more complex ones here).

Michael Levin has some interesting things to say about DNA as essentially the “hardware” layer of living things, DNA being the encoding needed to manufacture proteins, but, at the multicellular level there appears to be a kind of swarm intelligence (like ants or bees), or as he’s sometimes put it “intent all the way down” where the scope progressively narrows on the way down. Some of his interviews have made it to YouTube (maybe start with his TED talk) and, if you listen to podcasts, there’s an interview with him on one of my favorite podcasts, Big Biology. Start there if you can. Fascinating stuff.