(A) The probability of selecting, uniformly at random from the host genome, a tRNA array that is able to encode as many anticodons as that carried by the phage is 0.0016. In addition, contiguous stretches of tRNA in the host genome, which are typically thought to be the result of duplication events, encode very lowly diverse anticodons. The phage’s tRNA collection, therefore, appears to be the result of multiple acquisition and selection events. (B) Of the tRNA not carried by the phage, most are highly expressed by the host, and others correspond to codons not very highly used by the phage genome.