Prokaryotes : Negatively charged DNA, is held with positively charged proteins, in nucleoid, DNA in nucleoid is organised in large loops held by protein.
Eukaryotes : In nucleus the negatively charged DNA, is wrapped around positively charged histone octomer, to form nucleosome, nucleosomes are repeated, to constitute chromatin, at higher level additional set of non-histone chromosomal protein gets associated with chromatin.
Detailed answer:
Packaging of DNA helix in prokaryotes : In prokaryotes there is no true nucleus. The DNA is present in a region called nucleoid. The DNA which is negatively charged is held with some positively charged nonhistones basic proteins. DNA in nucleoid is organized in large loops held by protein.
DNA Packaging in eukaryotes: In eukaryotes there is found true nucleus, chromosomes are made up of DNA and Histone proteins. The negatively charged DNA is wrapped around positively charged histone octamer (2 molecules each of H2A, H2B, H3 & H4) to form nucleosome which from the repeating units of chromatin Nucleosomes are further coiled and packed to form solenoids. Further super coiling forms chromatin fibers and then chromatids. This further coils and condenses at metaphase stage of cell division to form chromosomes.
