During transcription, RNA base pairing occurs with which DNA strand and in which orientation?

During transcription, RNA base pairing occurs with which DNA strand and in which orientation?

• A. The coding strand, read 5' to 3'
• B. The template strand, read 3' to 5'
• C. The coding strand, read 3' to 5'
• D. The template strand, read 5' to 3'

Answer: (B)

RNA polymerase uses the DNA template strand as its guide and moves along it in the 3' to 5' direction. As RNA is built 5' to 3', the new transcript is complementary and antiparallel to the template strand. That means base pairing occurs with the template strand in a 3' to 5' orientation, producing an RNA sequence that matches the coding strand except that uracil replaces thymine. The coding strand itself isn’t used as the template during transcription.

RNA polymerase uses the DNA template strand as its guide and moves along it in the 3' to 5' direction. As RNA is built 5' to 3', the new transcript is complementary and antiparallel to the template strand. That means base pairing occurs with the template strand in a 3' to 5' orientation, producing an RNA sequence that matches the coding strand except that uracil replaces thymine. The coding strand itself isn’t used as the template during transcription.