Cloning of alien DNA by the host involves -

Attaching at the specific sequence site (ori) in the host

The correct answer is Option (1) → Attaching at the specific sequence site (ori) in the host.

DNA cloning is a molecular biology technique used to make multiple identical copies of a specific DNA sequence or template DNA. DNA cloning is the process of producing identical copies of a specific DNA fragment. It typically involves inserting the DNA fragment into a vector (like a plasmid), which is then introduced into a host cell (often a bacterium). As the host cell grows and divides, it replicates the inserted DNA along with its own DNA. Origin of replication (ori) is a sequence from where replication starts and 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 support high copy number.