上游充通大警 SHANGHAI JIAO TONG UNIVERSITY Genome size of virus The largest known viral genome,that of bacteriophage G,is 670 kb. Some viruses have genomes so small they contain less than 5 genes. Bacterial genomes:Most are between 1000 and 5000 kb,with the smallest known being 580kb. Chen Feng,Shanghai Jiao Tong UniversityChen Feng, Shanghai Jiao Tong University Genome size of virus The largest known viral genome, that of bacteriophage G, is 670 kb. Some viruses have genomes so small they contain less than 5 genes. Bacterial genomes: Most are between 1000 and 5000 kb, with the smallest known being 580kb