The diagram below shows part of a DNA molecule. The length of a DNA double helix increases by 0.34 nm for every pair of nucleotides. The total number of nucleotides in a human body cell is 1.2 × 1010. Calculate the total length of double helix in a human body cell. Give your answer in metres. Use information from the diagram . – 6024

One thought on “The diagram below shows part of a DNA molecule. The length of a DNA double helix increases by 0.34 nm for every pair of nucleotides. The total number of nucleotides in a human body cell is 1.2 × 1010. Calculate the total length of double helix in a human body cell. Give your answer in metres. Use information from the diagram . – 6024”

1. First, I did 0.34 × 12,000,000,000 = 4,080,000,000
   (This gives the total length in picometres for 12 billion base pairs)

   Then I divided by 1,000,000,000 to convert picometres to metres:
   4,080,000,000 ÷ 1,000,000,000 = 4.08 m

   But DNA is double-stranded, so I divided by 2:
   4.08 ÷ 2 = 2.04 m

   So the final answer is: 2.04 metres

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