How long is your DNA?

The DNA inside each of your cells is longer than you are, but packs down into a space smaller than you can see.

18th July 2011
How long is your DNA? (Getty)

Asked by: Anonymous

The DNA in your cells is packaged into 46 chromosomes in the nucleus. As well as being a naturally helical molecule, DNA is supercoiled using enzymes so that it takes up less space.

Try holding a piece of string at one end, and twisting the other. As you add twist, the string creates coils of coils; and eventually, coils of coils of coils. Your DNA is arranged as a coil of coils of coils of coils of coils! This allows the 3 billion base pairs in each cell to fit into a space just 6 microns across.

If you stretched the DNA in one cell all the way out, it would be about 2m long and all the DNA in all your cells put together would be about twice the diameter of the Solar System.


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