KCET 2015 Biology Solved Paper

The vectors are DNA molecules that can carry foreign DNA segment and replicate inside the host cell. Plasmids are extra-chromosomal, self-replicating, circular, ds DNA molecules. Plasmid vectors are used to carry small DNA fragments usually of 100 — 1000 bp. Cosmids are used to clone DNA fragments upto 45kb in length, bacterial artificial chromosomes (BAC) can accommodate 300-350kb of foreign DNA and yeast artificial chromosomes (YAC) can clone DNA fragments of more than 1 Mb in size.