Which enzyme synthesizes RNA using a DNA template during transcription?

• A. RNA Polymerase
• B. DNA Polymerase
• C. Ligase
• D. Topoisomerase

Answer: (A)

RNA polymerase is the enzyme responsible for synthesizing RNA using a DNA template during transcription. It binds to promoter regions, unwinds a small segment of DNA, and then adds ribonucleotides complementary to the DNA template strand, building the RNA in the 5' to 3' direction. It does not require a primer, unlike DNA polymerase, which is used for DNA replication and needs a primer to start synthesis. DNA polymerase copies DNA, ligase seals breaks to join DNA fragments, and topoisomerase relieves torsional strain ahead of the fork. So, RNA polymerase is the enzyme that carries out transcription by making RNA from the DNA template.