Packaging DNA
Your cells are all invisible to the naked eye. Yet if the DNA in just one of them were to be stretched out, it would be about two metres long. Instead, it is all bundled into the cell nucleus, which has a diameter of just five-thousandths of a millimetre. This is like trying to cram 2000 kilometres of wool into an average-sized room. All your DNA is tightly coiled up around proteins, then wound up again until it is 'supercoiled'.
