NEETZoologyBiotechnology - Principles and Processes
A researcher ligates a gene of interest into the EcoR I restriction site of the cloning vector pBR322 and introduces the resulting mixture into competent E. coli cells. Which of the following statements regarding this experiment is incorrect?
Options
- AThe recombinant plasmid confers resistance to both ampicillin and tetracycline.
- BRecombinant transformants can be distinguished from non-recombinants by replica plating on antibiotic-containi
- CThe EcoR I recognition sequence is located outside the selectable marker genes in pBR322.
- DBoth recombinant and non-recombinant transformants will form colonies on a medium containing ampicillin.
Correct answer
B. Recombinant transformants can be distinguished from non-recombinants by replica plating on antibiotic-containi
Step-by-step solution
In the cloning vector pBR322, the EcoR I restriction site is located outside both the ampicillin resistance and tetracycline resistance genes. Therefore, insertion of an alien DNA at the EcoR I site does not cause insertional inactivation of either selectable marker. Both recombinant and non-recombinant plasmids will continue to confer resistance to ampicillin and tetracycline. Because their antibiotic resistance profiles are identical, replica plating on antibiotic-containing media cannot be used to distinguish re