19 agosto 2014
Before cells divide, they create so much genetic material that it must be wound onto spools before the two new cells can split apart. These spools are actually proteins called histones, and they must multiply at the same moment that the cell doubles its DNA. If the amount of histones does not increase when the DNA doubles, the centimeters of new DNA could never be packed small enough to fit into chromosomes, which are just a few micrometers long. In the early stage of development, the period when DNA doubles and the cell divides is called proliferation, after which an embryo grows from one cell to more than one thousand cells.
http://feeds.sciencedaily.com/~r/sciencedaily/~3/hiAoZO2FsR8/140819083211.htm
