Which of the following statement is correct regarding the process of replication in E. coli? [2024]
The DNA dependent DNA polymerase catalyses polymerisation in one direction that is 3′ → 5′.
The DNA dependent RNA polymerase catalyses polymerisation in one direction that is 5′ → 3′.
The DNA dependent DNA polymerase catalyses polymerisation in 5′ → 3′ as well as 3′ → 5′.
The DNA dependent DNA polymerase catalyses polymerisation in 5′ → 3′ direction.
(4)
The DNA-dependent DNA polymerases catalyses polymerisation only in one direction, that is 5' → 3'. This creates some additional complications at the replication fork. Consequently, on one strand (the template with polarity 3' → 5'), the replication is continuous, while on the other (the template with polarity 5' → 3') it is discontinuous.
Ten E. coli cells with -dsDNA are incubated in medium containing nucleotide. After 60 minutes, how many E. coli cells will have DNA totally free from ? [2022]
20 cells
40 cells
60 cells
80 cells
(3)
E. coli divides in 20 minutes. After 60 minutes, generation III would have 75% DNA completely free from and 25% of DNA would be hybrid . So, out of 80 cells formed, 60 cells will be free from DNA.
During DNA replication, Okazaki fragments are used to elongate [2017]
the lagging strand towards replication fork
the leading strand away from replication fork
the lagging strand away from the replication fork
the leading strand towards replication fork
(3)
Lagging strand is a replicated strand of DNA which is formed in short segments called Okazaki fragments. Its growth is discontinuous. The direction of growth of the lagging strand is 3' → 5' though in each Okazaki fragment it is 5' → 3'.
