sentence: Histones act as spools around which DNA winds, and play a role in gene regulation.
sentences_after: Without histones, the unwound DNA in chromosomes would be very long. For example, each human cell has about 1.8 meters of DNA, but wound on the histones it has about 90 millimeters of chromatin, which, when duplicated and condensed during mitosis, result in about 120 micrometers of chromosomes.
concept_name: histone
headings: Histone
categories: Molecular biology Cell biology