Question

DNA replication requires which of the following enzymes?
A. DNA polymerase only
B. DNA polymerase and ligase
C. Ligase only
D. RNA polymerase

Answer 1

Hint:Helicase opens up the DNA at the replication fork. To avoid rewinding of the DNA, Single-strand binding proteins coat the DNA all over the replication fork. Topoisomerase operates in the region prior to the replication fork to prevent supercoiling. Primase synthesizes RNA primers complementary to the DNA strand. In order to produce a bulk of the new DNA, DNA polymerase III expands its primers and adds them to the 3' end. RNA primers are removed and replaced with DNA by DNA polymerase I. DNA ligase sealed the gaps between DNA fragments.

Complete answer:
DNA replication in molecular biology is the biological process by which two identical DNA replicas are produced from a single original DNA molecule. DNA replication is most important to the biological heritage in all living organisms. The cell has a distinctive characteristic of dividing that makes it essential to replicate DNA. DNA consists of two complementary strands of a double helix. Such strands are divided during replication. Each strand of the original DNA molecule then works as a template for the formation of its counterpart, a process termed as semiconservative replication. As a result of semi-conservative replication, the new helix will be made up of an original DNA strand and also a newly synthesised strand. Mechanisms for cellular editing and error management make DNA replication almost ideal.

DNA polymerase enzyme is one of the main molecules for DNA replication. DNA polymerases synthesize the DNA: add nucleotides to the growing DNA chain one by one, with only those complementing the template. Other enzymes, such as DNA primase, DNA helicase, DNA ligase, and topoisomerase, are necessary for replication of DNA.

Thus, the correct answer is option B. i.e., DNA polymerase and ligase.

Note:DNA replication is Semiconservative replication. Each double-helix strand acts as the template for the complementary synthesis of a new strand. New DNA consists of enzymes called DNA polymerases requiring a template and a first and synthesizing DNA in 5 'to 3' direction. A new strand is formed as a continuous part during DNA replication. The other is made in small pieces.