Hi Great question. ITs really just to do with size, bacteria have much much smaller genomes than us and socomaratively bigger spaces to put it into, so they can just circularise (some are linear, but most are circular), this stops tangling also. OUr genomes are much bigger and so have to be really tightly coiled around proteins to get them into the nucleus of the cells, ending up in the x structure of the chromosomes. Ask again if this doens’t make sense or you want more info.
EEp!! this is definitly not my are of expertise though i think Andrew might be the many of the moment for this question or Louisa aswell!!if you have any psych, nutrition or health questions let me know-I’m off to find that programme-educate myself on the world of chromosomes-cheers!!