Question

How does ORI decide the copy no. of a plasmid?

Answer 1

ORI is the origin of replication where the replication of the plasmid starts. If the Ori can support faster replication , then the copy number of plasmids will be more.If it supports lesser number , the plasmid copy will be less.
So the number of plasmidds produced depends on the ORI of the plasmid.Some plasmids produce more number of replicated plasmids and others produce less number of replicated plasmids based on thier ORI.