Human genome is about 3x109 base pairs long. At 0. 34 nm per base pair in the double helix, that"s 102cm. 2 copies of each chromosome per cell. Human dna must be condensed about 10 000-fold to it inside nucleus. Despite being condensed, dna must remain available for replicaion, repair and gene transcripion. Eukaryoic dna is condensed with the help of specialized proteins. Dna must be organized in order to access the genes; can"t be random. If you want to access a speciic dna porion, cannot get it if it"s in an analogy of the twine ball. Highly conserved eukaryoic proteins involved in condensing dna (prokaryotes use diferent proteins) (only eukaryotes have histones) Contain fewer than 200 amino acids (very small) Rich in lysine and arginine residues (so it is posiively charged to interact with negaively charged dna) To interact, proteins and dna are oppositely charged. Ive types: h1, h2a, h2b, h3 and h4.