Give the importance of the origin of replication in a chromosome.

(N/A) In recombinant $DNA$ technology,a piece of $DNA$ is transferred into an alien organism.
- This piece of $DNA$ would not be able to multiply itself in the progeny cells of the organism.
- However,when it gets integrated into the genome of the recipient,it may multiply and be inherited along with the host $DNA$. This is because the alien piece of $DNA$ has become part of a chromosome,which has the ability to replicate.
- In a chromosome,there is a specific $DNA$ sequence known as the 'origin of replication' $(ori)$,which is responsible for initiating replication.
- Therefore,for the multiplication of any alien piece of $DNA$ in an organism,it needs to be a part of a chromosome that has a specific sequence known as the 'origin of replication'.
- Thus,an alien $DNA$ is linked with the origin of replication so that this alien piece of $DNA$ can replicate and multiply itself in the host organism. This process is also called cloning.