Question

which action is one role of rna polymerase during transcription?

• to break down an already existing protein
• to produce a start sequence
• to switch uracil with thymine on the exposed gene
• to build a molecule of mrna

Explanation:

RNA polymerase synthesizes mRNA during transcription. It reads the DNA template strand and builds a complementary mRNA molecule. It does not break down proteins, switch uracil with thymine (uracil is in RNA and thymine in DNA and this is not its role in transcription), or produce a start - sequence in the sense described. Its main role is to build mRNA.

Answer:

to build a molecule of mRNA