Question

Problem 10.23 in book: There are 3.4 billion base pairs lined up end to end in one human DNA molecule, which contains the entire genetic code for the makeup of an individual person. Each base pair measures approximately 350 pm in length, and almost every cell in the body contains two complete DNA molecules. (a) If one DNA molecule was stretched end to end, how far would it stretch

Answer 1

Solution :

The total number of the base pairs in a human DNA molecule is given as

= 3.4 billion

= 3,400,000,000

The length of each of the pair of DNA  = 350 pm

                                                            $=350 \times 10^{-12} \ m$

a). Therefore the maximum length of the DNA when it is completely stretched end to end can be found out as  $=350 \times 10^{-12} \times 3,400,000,000$

                                                                  = 1.19 m

                                                                  = 0.00119 km

Now 1 km = 0.6213711 miles

∴ 0.00119 km would be = 0.00119  x 0.6213711

                                     = 0.000739432 miles.