What is transcription?

• A. The process of translating a DNA sequence into a protein.
• B. The process of copying a DNA sequence into an RNA molecule.
• C. The process of replicating DNA.
• D. The process of editing RNA transcripts.

Answer: (B)

Transcription is the process of copying a DNA sequence into an RNA molecule. It’s the first step in gene expression. During transcription, RNA polymerase binds to a promoter on the DNA, reads the template strand, and builds a complementary RNA strand by pairing nucleotides (A with U in RNA, T with A, C with G, G with C). The result is an RNA transcript that can become mRNA, tRNA, or rRNA depending on the gene.

In many organisms, transcription is followed by RNA processing in eukaryotes (adding a 5' cap, a poly-A tail, and removing introns) before the RNA becomes functional. Transcription differs from translation, which is the process of using the RNA sequence to assemble a protein, and from DNA replication, which copies the entire DNA molecule. Editing RNA transcripts refers to processing steps after transcription, not transcription itself.