​Which one of the following statements about RNA polymerase in eukaryotes is INCORRECT?​

Correct option is C

Explanation:

• (1): Correct. RNA polymerase I is responsible for synthesizing the 18S, 5.8S, and 28S rRNAs which are components of the ribosomal RNA in eukaryotes.

• (2): Correct. RNA polymerase II synthesizes mRNA in eukaryotic cells, which is crucial for protein coding and gene expression.

• (3): Incorrect. RNA polymerase II does not require a sigma factor (σ) to initiate transcription. The sigma factor is a component of RNA polymerase in prokaryotes (such as in E. coli), not in eukaryotes. In eukaryotes, RNA polymerase II requires general transcription factors (GTFs) for transcription initiation, such as TFIID, which binds to the TATA box of the promoter region.

• (4): Correct. RNA polymerase III synthesizes 5S rRNA and tRNA, both of which are involved in protein synthesis.

Information Booster:

1. RNA polymerase I is responsible for the synthesis of rRNA (18S, 5.8S, 28S) in the nucleolus.

2. RNA polymerase II synthesizes mRNA and is essential for the transcription of protein-coding genes.

3. RNA polymerase II requires general transcription factors to initiate transcription, and does not require a sigma factor, which is specific to prokaryotic transcription.

4. RNA polymerase III synthesizes small RNAs, including tRNAs and 5S rRNA, which are involved in the assembly of ribosomes and translation.