How long is a section of a DNA molecule with a molecular weight of 10200

How long is a section of a DNA molecule with a molecular weight of 10200, if the mass of one nucleotide is about 300, and the length of a pair of nucleotides is 0.34 nm.

1) First, let’s find the number of nucleotides. To do this, divide the molecular weight of a DNA segment by the weight of one nucleotide:

10200/300 = 34 nucleotides. Because DNA has the form of a double helix, 34/2 = 17 nucleotides on each of the strands.

2) The phrase “length of a base pair” means the distance between two base pairs as well as between two adjacent nucleotides. To find the length of a double helix, you need to multiply the number of nucleotides in one strand by the length of a pair of nucleotides:

17 * 0.34 = 5.78 nm.