What is the size of the human DNA (Deoxyri-bonucleic acid) molecule?

The chromosomes in the nucleus of a cell contain all the information a cell needs to carry on its life processes. They are made up of a complex chemical (a nucleic acid) called deoxyribonucleic acid or DNA for short. DNA is the hereditary material of all cells. It is a double-stranded helical molecule consisting of nucleotide monomers (building blocks of more complex molecules, called polymers). In the chromosomes of a cell, DNA occurs as fine, spirally coiled threads that in turn coil around another, like a twisted ladder (see picture). An adult human being has approximately 1,00,000 billion cells, and each cell has a twisted string of DNA. The width of each DNA is not more than 0.0000000001 centimetres. Size of all the DNA of a human body put together would be 175 cen-timetres. If we shrink the width to the thickness of a violin string, the length would extend up to 15 kilometres. How-ever, if we join the DNA of each cell end to end in its original size, its length would be nearly 175 billion kilometres—that's almost 12 times distance between the Earth and the Sun. It is a miracle of nature that we human beings go about our daily chores throughout our life carrying this immensely long string of DNA, within which incessant biological activity goes on round the clock.