NEETZoologyBiotechnology - Principles and Processes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Selection of recombinants due to inactivation of antibiotics is considered a cumbersome procedure. Reason (R): It requires simultaneous plating on two plates having different antibiotics. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- BBoth (A) and (R) are correct and (R) is the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
B. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
According to NCERT, the selection of recombinants using antibiotic resistance genes (like in pBR322) is a cumbersome procedure because it requires simultaneous plating on two plates having different antibiotics. For instance, to identify recombinants, one must first plate the transformants on an ampicillin-containing medium, and then replica-plate the growing colonies onto a tetracycline-containing medium. Due to this practical difficulty, alternative selectable markers (like chromogenic substrates) were developed.