Question

Which of the following statement is correct regarding the process of replication in E.coli?

• A. The DNA dependent DNA polymeras catalyses polymerization in one direction that is 3'$→$5'.
• B. The DNA dependent RNA polymeras catalyses polymerization in one direction that is 5'$→$3'.
• C. The DNA dependent DNA polymeras catalyses polymerization in 5'$→$3' as well as 3'$→$5' direction.
• D. The DNA dependent DNA polymeras catalyses polymerization in 5'$→$3' direction.

Answer 1

Answer: (D)

The DNA dependent DNA polymeras catalyses polymerization in 5'$→$3' direction.

Answer 2

In E. coli, DNA replication is catalyzed by DNA-dependent DNA polymerase, which only works in the 5’ → 3’ direction. This polymerase synthesizes the new strand in this direction while the template strand is read in the 3’ → 5’ direction. RNA polymerase catalyzes transcription in the 5’ → 3’ direction, but it does not synthesize DNA.