1 - Question
What will be the consequence of not having an origin of replication (ori) in the vector?
a) If an ori is absent, replication of vector would not take place
b) As the cells divide after taking up the vector, both the daughter cells would be having the vector
c) A colony of transformed colonies is observed
d) The vector won’t be taken up by the cell
Explanation: In the case ori is absent, the vector won’t be able to replicate. As the replication won’t take place, only one of the daughter cells would be having the vector. A colony of transformed colonies won’t be obtained. The puc18 ori came from a plasmid in clinical bacterial isolate and was called as pMB1
2 - Question
It is required to distinguish between the cells that have taken up the vector and that have not. It is done by using __________
a) multiple cloning site
b) origin of replication
c) high copy number
d) selectable marker
Explanation: Whether the cell has taken up the vector or not is distinguished by using a selectable marker. A selectable marker often used is the ampcillin resistance property. Cells having the plasmid or vector show resistance against ampicillin.