Practice question

Plasmid-based vectors are derived from extrachromosomal circular bacterial plasmids engineered to carry foreign DNA, including pBR322, pUC series, cosmid and bacterial artificial chromosome containing F-factor origin. Yeast artificial chromosome is fundamentally distinct, constructed to behave as a eukaryotic chromosome. It contains centromere, telomeres, autonomously replicating sequence, selectable markers URA3 and TRP1, and replicates in Saccharomyces cerevisiae rather than Escherichia coli alone. Despite containing bacterial sequences for shuttling, YAC architecture mimics yeast chromosome, not bacterial plasmid, therefore classified separately from plasmid-based systems.