Process By Which Cells 'Hide' Potentially Dangerous DNA Segments Explained

The **DNA** in the 23 pairs of chromosomes in each of the billions of cells of the human body is so tightly packed that it would measure six feet in length if stretched end to end. A genome of this size can squeeze into a cell's tiny nucleus because it is compressed into highly condensed **chromatin** fibers by proteins called **histones**. All chromatin in the cell nucleus represents a massive condensation of the genetic material. But a portion of it might well be called super-condensed; it forms a kind of chromatin called **heterochromatin**. The genes contained within these portions of the genome are effectively "silenced" because they cannot be accessed by the cell's DNA-activating machinery. More information "Sciencedaily.com":[ http://www.sciencedaily.com/releases/2009/04/090409185406.htm]

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