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True or false:

The RNA polymerase used by the cell to initiate DNA synthesis is the identical RNA polymerase used by the cell for transcription.

1 Answer

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Final answer:

The statement is false; RNA polymerase is used for transcription, not for initiating DNA synthesis. Prokaryotic organisms like E. coli use a RNA polymerase composed of multiple subunits, including a sigma factor for transcription initiation. Eukaryotic cells have separate RNA polymerases for different RNA types.

Step-by-step explanation:

The statement is false. The RNA polymerase used by the cell to initiate DNA synthesis is not identical to the RNA polymerase used for transcription. In the transcription process, RNA polymerase is indeed the key enzyme, utilizing the DNA template to catalyze the synthesis of a complementary RNA strand. However, the enzyme responsible for initiating DNA synthesis, typically referred to as a DNA polymerase, uses a different set of substrates and has a different function compared to RNA polymerase. In prokaryotic cells such as E. coli, the RNA polymerase holoenzyme, which is essential for transcription initiation, consists of the core enzyme plus a sigma (σ) factor that recognizes the promoter sequences on the DNA template. In eukaryotic cells, multiple forms of RNA polymerase are specialized for transcribing different types of RNAs, such as mRNA, tRNA, and rRNA.

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