What is transcription?

• A. The synthesis of DNA from a DNA template
• B. The synthesis of RNA from a DNA template
• C. The synthesis of protein from RNA
• D. The replication of RNA

Answer: (B)

Transcription is the process by which a gene’s information stored in DNA is copied into an RNA molecule. RNA polymerase reads a DNA template strand and builds a complementary RNA strand by adding ribonucleotides, producing RNA that can be mRNA, tRNA, or rRNA. In eukaryotes, this happens in the nucleus and the initial transcript is processed to become mature mRNA; in prokaryotes it occurs in the cytoplasm and can be used directly for protein synthesis. This is different from DNA replication, which makes a DNA copy, and from translation, which uses RNA to synthesize protein.