Our genetic information or genome is stored in the parts of the DNA molecule called base pairs. Our genome contains about 3 billion 3 imes 109 base pairs, and there are two copies in each cell. Along the DNA molecule, there is one base pair every one-third of a nanometer. How long would the DNA helix from one cell be if it were stretched out in a line? If the entire DNA molecule were wrapped up into a sphere, what would be the diameter of that sphere?