Question

If the distance between two consecutive base pairs is 0.34nm 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. 2.0 meters
• B. 2.5 meters
• C. 2.2 meters
• D. 2.7 meters

Answer 1

Answer: (C)

2.2 meters

Answer 2

Length of DNA = Number of base pairs $\times 0.34\, nm$ $= 6.6 \times 10^9 \times 0.34 \,nm$ $= 6.6 \times 10^9 \times 0.34 \times 10^{-9} m$ $= 2.2 \,m$