NEETZoologyBiotechnology - Principles and Processes
A researcher successfully inserts a gene of interest into a plasmid vector but accidentally deletes the 'ori' (origin of replication) sequence from the vector before transforming it into a competent bacterial host cell. What will be the ultimate fate of this recombinant plasmid inside the host?
Options
- AIt will replicate independently in the cytoplasm but at a much slower rate.
- BIt will fail to initiate replication and will eventually be lost as the host cell divides.
- CIt will utilize the host chromosome's 'ori' to replicate autonomously in the cytoplasm.
- DIt will replicate normally because the host cell provides the necessary DNA polymerase.
Correct answer
B. It will fail to initiate replication and will eventually be lost as the host cell divides.
Step-by-step solution
The 'ori' (origin of replication) is a specific DNA sequence responsible for initiating replication. For any piece of DNA to multiply autonomously within a host cell, it must contain this sequence. Even though the host cell provides enzymes like DNA polymerase, replication cannot start without the 'ori' sequence acting as the initiation site. Therefore, the recombinant plasmid lacking an 'ori' will not be able to replicate independently. As the host cell divides, the non-replicating plasmid will not be distributed