Describe why transcription is so important for translation

mRNAs enable the cell to express only the genes it wants, not the entire DNA genome. These mRNAs exit the nucleus so they can be then translated in the cytosol. ... Varying mRNA creation (transcription), lifespan etc. also allows the cells to fine tune better how much of and when they want to produce a protein.

Explanation:

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.