Amino acid variability among the proteins encoded by related genes from pathogenicity islands located in different bacterial strains and species can best be accounted for by
A. random mutation
B. directed mutation
C. horizontal gene transfer
D. vertical gene transfer
Answer:A
Amino acid variability among the proteins encoded by related genes from pathogenicity islands located in different bacterial strains and species can best be accounted for by
A. random mutation B. directed mutation C. horizontal gene transfer D. vertical gene transfer