Answer:
25%
Step-by-step explanation:
The approximate proportion of G + C content in the genome of E. coli has been reported to be 50%. According to Chargaff's rule, the amount of guanine in any DNA must be approximately equal to the amount of cytosine. Hence,
if G + C = 50 and G = C,
then
G = C = 25
Therefore, the approximate percentage of guanine in the genome of E. coli would be 25.