Zoology - Biotechnology - Principles and Processes Question with Solution | TestHub

Plasmids and bacteriophages are used as cloning vectors. Bacteriophages have very high copy numbers as compared to plasmids which have only one or two copies per cell or may go up to 15-100 copies per cell. Origin of replication (ori) is the sequence from where replication starts. When a piece of DNA is linked to this Ori site it can be made to replicate within the host cells. Ori site is also responsible for controlling the number of copies made. As bacteriophages create a lot of copies it may lead to confusion where as plasmids which have few or at times single site of origin of replication they are preferred to be used as a vector. Therefore the most important feature in a plasmid to be used as a vector is Ori.