Explanation

Each species has a characteristic content of DNA, which is constant in all the individuals of that species and has thus been called the C-value. Eukaryotes vary greatly in DNA content but always contain much more DNA than prokaryotes. Lower eukaryotes have less DNA such as nematode $Caenorhabditis\ elegans,$ which has only 20 times more DNA then $E.\ coli$ or the $Drosophila$, which has 40 times more DNA ($ie$., 0.18 pg). Man has about $3.2 \times 10^{9}$bp of DNA per haploid genome. This huge variation in C-value between species is called C-value paradox.