Question

The given figure is the diagrammatic representation of the $E.coli$ vector $pBR322$. Which one of the given options correctly identifies its certain components?

• A. $ori-$original restriction enzyme
• B. $rop-$reduced osmotic pressure
• C. $HindIII,EcoRI$ - selectable markers
• D. $am{p}^R,te{t}^R$ - antibiotic resistance genes

Answer 1

The correct option is D $am{p}^R,te{t}^R$ - antibiotic resistance genes

The plasmid is a naturally occurring, extrachromosomal, circular, double-stranded DNA that can replicate autonomously. It has been manipulated to act as vector for the biotechnological processes.

A. ori is the origin of replication region of the plasmid from where the replication can initiate.

B. rop region codes for a protein that maintains the copy number of plasmid in the cell.

C. Hind III, EcoRI are the sites on the plasmid that can be recognized by their respective restriction endonuclease and cut can be made so that gene-of-interest can be inserted.

D. amp${}^R$, tet${}^R$ are the selectable markers or the antibiotic resistance genes that confer resistance against the ampicillin and the tetracycline and allow the selection of the transformed host cell in a culture.

So, the correct answer is 'amp${}^R$, tet${}^R$ - antibiotic resistance genes'