Transcription directionality — During RNA synthesis, what RNA sequence is produced from the DNA template strand 5′-T p A p G p C-3′ (written 5′→3′ on the template)?

Introduction:
Transcription produces RNA complementary to the DNA template and antiparallel to it. Getting orientation correct is essential for predicting RNA sequences from DNA and vice versa.

Given Data / Assumptions:

• Template strand is explicitly given 5′→3′ as T–A–G–C.
• RNA uses U instead of T.
• Polymerases synthesize RNA 5′→3′ while reading the template 3′→5′.

Concept / Approach:
Because the provided template is written 5′→3′, we must first reverse its orientation to align with the polymerase reading direction. Complement bases accordingly and then express the RNA in the standard 5′→3′ direction.

Step-by-Step Solution:

Verification / Alternative check:
Check against the non-template (coding) strand: it would be 5′-G C T A-3′ in DNA, so replacing T with U gives 5′-G C U A-3′ in RNA, matching the result.

Why Other Options Are Wrong:

Common Pitfalls:
Forgetting antiparallel orientation; writing T in RNA; failing to reverse the template before complementing.

Final Answer:
5′-G p C p U p A-3′.