Teaching CSIR NET Mock Test Series Life Sciences Fundamental Processes DNA replication, repair and recombination
Asynchronous cultures of E. coli were grown in 14N and then shifted to 15N medium containing a chemical C (0 minute) and incubated for two generation times (i.e. 40 minutes). Proportion of hybrid DNA (14N-15N) was measured at various time-points and results are depicted in the following table.
| Time | 0 minute | 10 minutes | 20 minutes | 30 minutes | 40 minutes |
| Hybrid DNA | 0% | 40% | 40% | 40% | 40% |
From the data, it was concluded that the chemical C inhibits DNA replication.
Which one of the following possibilities could be the likely mode of action of chemical C?
1
It inhibits the initiation of replication.
2
It inhibits the elongation phase of replication.
3
It inhibits the termination of replication.
4
It competes with dNTPs for incorporation into the newly synthesized DNA.