Which enzyme reads the original DNA strand and adds complementary nucleotides to synthesize a new strand?

Which enzyme reads the original DNA strand and adds complementary nucleotides to synthesize a new strand?

• A. RNA polymerase
• B. DNA polymerase
• C. DNA ligase
• D. Helicase

Answer: (B)

DNA polymerase is the enzyme that reads the template DNA strand and builds the new complementary strand. It scans the existing strand in the 3' to 5' direction and adds nucleotides to the growing strand in the 5' to 3' direction, pairing each base with its complement (A with T, G with C). It also checks and corrects mistakes as it goes, which helps ensure accurate replication. The other enzymes perform different tasks: RNA polymerase makes RNA and is involved in transcription (and primers in DNA replication), DNA ligase seals gaps between fragments, and helicase unwinds the double helix to allow replication to happen.

DNA polymerase is the enzyme that reads the template DNA strand and builds the new complementary strand. It scans the existing strand in the 3' to 5' direction and adds nucleotides to the growing strand in the 5' to 3' direction, pairing each base with its complement (A with T, G with C). It also checks and corrects mistakes as it goes, which helps ensure accurate replication. The other enzymes perform different tasks: RNA polymerase makes RNA and is involved in transcription (and primers in DNA replication), DNA ligase seals gaps between fragments, and helicase unwinds the double helix to allow replication to happen.