Question

If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is $6.6\times {10}^9$ bp, then the length of the DNA is approximately

• A. 2.2 metres
• B. 2.7 metres
• C. 2.0 metres
• D. 2.5 metres

Answer 1

The correct option is A 2.2 metres

The diploid content of the human genome is $6.6\times {10}^9$ bp base pairs. The distance between two consecutive base pairs is 0.34 nm $(0.34\times {10}^{-9}m),$ so the length of DNA double helix in a typical mammalian cell is around

= $6.6\times {10}^{-9}$ bp x $0.34\times {10}^{-9}m/bp$
= 2.2 metres