Practice question

Yeast vectors are categorized by replication behavior. Yeast replicative plasmid YRp carries ARS but lacks centromere, replicates autonomously but unstable. Yeast centromere plasmid YCp contains ARS plus CEN, single-copy stable. Yeast episomal plasmid YEp contains 2-micron origin, high-copy. Yeast integrative plasmid YIp lacks ARS and yeast origin, cannot replicate autonomously, so must integrate into host chromosome via homologous recombination for stable inheritance. Integration occurs at homologous loci, providing stable single copy but low transformation frequency, useful for gene disruption and stable expression studies.