NEET BIOLOGY

Detailed explanation-1: -In prokaryotic cells, polymerase III is the major replicative polymerase, functioning in the synthesis both of the leading strand of DNA and of Okazaki fragments by the extension of RNA primers. Polymerase I then removes RNA primers and fills the gaps between Okazaki fragments.

Detailed explanation-2: -The RNA primers are removed by the exonucleases Fen1 and/or Dna2, and the gaps are filled by the DNA polymerase that is already working on the lagging strand. As in bacteria, the nicks are sealed by DNA ligase. Eukaryotic replisomes are more complex than bacterial replisomes.

Detailed explanation-3: -DNA Polymerase Only Moves in One Direction As previously mentioned, DNA polymerase can only add to the 3’ end, so the 5’ end of the primer remains unaltered. Consequently, synthesis proceeds immediately only along the so-called leading strand. This immediate replication is known as continuous replication.

Detailed explanation-4: -RNA primers are removed and replaced with DNA by DNA polymerase I. The gaps between DNA fragments are sealed by DNA ligase.

Detailed explanation-5: -DNA polymerase epsilon () is primarily responsible for leading strand replication and DNA polymerase delta () is responsible for synthesis of Okazaki fragments and lagging strand replication.