G + C content of prokaryotes is

G + C content of prokaryotes is 20%.
GC content is found to be variable with different organisms, the process of which is envisaged to be contributed to by the variation in selection, mutational bias, and biased recombination-associated DNA repair.
The average GC content in human genomes ranges from 35% to 60% across 100-Kb fragments, with a mean of 41% and in prokaryotes, it is near 20%.