The nucleotides are joined to each other by an enzyme called DNA __________.

The nucleotides are joined to each other by an enzyme called DNA __________.

• A. Ligase
• B. Helicase
• C. Primase
• D. Polymerase

Answer: (D)

Joining nucleotides during DNA synthesis is carried out by DNA polymerase, which catalyzes the formation of phosphodiester bonds that link nucleotides into the growing strand using the template strand. It adds new nucleotides one by one in the 5' to 3' direction, guided by base pairing and using dNTPs as substrates. Other enzymes have different roles: helicase unwinds the DNA double helix, primase lays down an RNA primer to start synthesis, and ligase seals nicks to join fragments after primers are removed. The essential point is that the linking of individual nucleotides to form the backbone of the new DNA strand is carried out by DNA polymerase.

Joining nucleotides during DNA synthesis is carried out by DNA polymerase, which catalyzes the formation of phosphodiester bonds that link nucleotides into the growing strand using the template strand. It adds new nucleotides one by one in the 5' to 3' direction, guided by base pairing and using dNTPs as substrates. Other enzymes have different roles: helicase unwinds the DNA double helix, primase lays down an RNA primer to start synthesis, and ligase seals nicks to join fragments after primers are removed. The essential point is that the linking of individual nucleotides to form the backbone of the new DNA strand is carried out by DNA polymerase.