the negatively charged DNA is wrapped around the histone octamer to form a structure called a nucleosome, which appears as 'beads-on-string'. This structure is then further packaged to form chromatin fibers. The association of the linker histone H1 (often shown in the diagram associated with the nucleosome text) seals the DNA as it enters and leaves the nucleosome, facilitating the condensation of the 'beads-on-string' into the more compact chromatin fibre.