Question

What is the length of human DNA containing $6.6\times {10}^9$ bp nitrogen bases?

• A. $22$nm
• B. $0.22$mm
• C. $2.2$m
• D. $22$m

Answer 1

The correct option is C $2.2$m

The distance between two consecutive base pair is 0.34 nm ($0.34X{10}^{-9}m$). The length of DNA for human diploid cell is $6.6X{10}^9$ bp x $0.34X{10}^{-9}m$ =2.2 metres. This length is far greater than the dimension of a typical nucleus which is approximately ${10}^{-6}m$. The long-sized DNA can be accommodated in the small area only through packaging or compaction.