Which process copies a gene's base sequence into an RNA molecule?

• A. Replication
• B. Transcription
• C. Translation
• D. Translocation

Answer: (B)

Transcription is the process that copies a gene’s base sequence into an RNA molecule. During transcription, RNA polymerase binds to a gene’s promoter, unwinds the DNA, and reads the template strand to synthesize RNA in the 5’ to 3’ direction. It pairs DNA bases with RNA bases (A with U, C with G, G with C, T with A on the template strand), producing an RNA sequence complementary to the DNA template and essentially identical to the gene’s coding region except that uracil replaces thymine. The RNA produced can be messenger RNA, transfer RNA, or ribosomal RNA, depending on which gene is being transcribed. This is different from replication, which duplicates the entire genome for cell division, and from translation, which uses RNA to assemble proteins. Translocation is movement that occurs during translation, not the copying of DNA into RNA.