Answer
If the diameter of the DNA equaled the diameter of extension cord, the extension would be 2500 km. 2500 km would be distance from London to Istanbul. The bases would 0.85 mm close to each other. 1000 nucleotide pair would be 85 cm long.
Work Step by Step
$(5 * 10^{-3})$ / $(2 * 10^{-9})$m = $(2.5 * 10^{6})$ factor. Consequently, the cord would be 2500 km. This is the distance between Istanbul to London. The nucleotides would be 0.85 mm close to each other. 1000 nucleotide pairs would be 85 cm $(0.85mm * 1000)$
