What is 'Ori' ? State its importance during cloning of a vector.
The origin of replication (ori) is a sequence from where replication starts. Any piece of DNA, when linked to this sequence, can be made to replicate within the host cells. This sequence is also responsible for controlling the copy number of the linked DNA. So, if one wants to recover many copies of the target DNA it should be cloned in a vector whose origin supports high copy number.