The template strand is given below
3'-ATGCAT-5'
The right coding strand for this will be
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 5'-TACGTA-3'
The coding strand has the same sequence as the RNA (with T for U) and is complementary to the template, running the opposite way. Template 3′-ATGCAT-5′ gives coding strand 5′-TACGTA-3′.
Option (1) 3'-TACGTA-5' — Incorrect. The bases are right, but the strand must run 5′ to 3′.
Option (2) 5'-TACGTA-3' — Correct. The coding strand has the same sequence as the mRNA (with T for U) and runs opposite to the template. Pairing A with T and G with C against 3′-ATGCAT-5′ gives 5′-TACGTA-3′.
Option (3) 3'-ATGCAT-5' — Incorrect. This is the template itself.
Option (4) 5'-UACGUA-3' — Incorrect. DNA has T, not U.