The distribution of the top ten significantly under-represented and the top ten significantly over-represented codon pairs in the organisms studied. The colored cells mark significant bias of the pattern in the corresponding organisms (observed/expected ≤ 0.90 (yellow) or observed/expected ≥ 1.10 (blue), p-value ≤ 0.01). Names of organisms with fewer than five biased codon pairs out of 20 are colored red. The percentages of biased codon pairs in full genomes and in standardized genomes and genome sizes are also shown. Yellow shaded cells – less than 10% of biased codon pairs in full genomes; less than 5% of biased codon pairs in standardized genomes; genomes smaller than 2 Mb. st. genome – standardized genome.