RNA polymerase II does not require a primer to initiate transcription. This makes option (A) the statement that is NOT true, as it is a key distinction from DNA polymerases used in replication.​

Option Analysis

Option (A): Requires primer
RNA polymerase II initiates transcription de novo using transcription factors like TFIIB, TFIIH, and a promoter complex, without needing a primer. DNA polymerases require primers, but RNA polymerases do not.​

Option (B): Copies one DNA strand
RNA polymerase II transcribes only the template strand of DNA into RNA at any given time, producing a complementary RNA copy in the 5’→3′ direction. Both strands are not transcribed simultaneously.​

Option (C): Does not synthesize rRNA/tRNA
RNA polymerase II transcribes mRNA precursors, snRNAs, and miRNAs, but not rRNA (mainly RNA polymerase I) or tRNA (RNA polymerase III). This statement holds true.​

Option (D): 5’→3′ polymerization
All nucleic acid polymerases, including RNA polymerase II, add nucleotides only to the 3′ end of the growing chain, synthesizing RNA in the 5’→3′ direction.​

RNA polymerase II transcription is central to eukaryotic gene expression, producing mRNA for protein synthesis. For CSIR NET aspirants, understanding its unique characteristics—like no primer requirement—helps master molecular biology questions. This article breaks down a classic MCQ on RNA polymerase II properties.​

Core Functions

RNA polymerase II forms a preinitiation complex with general transcription factors (TFIIA-H) at promoters, enabling de novo RNA synthesis without primers. It transcribes protein-coding genes from the template DNA strand only.​

• Handles mRNA, snRNA, miRNA precursors

• Sensitive to α-amanitin inhibition

• CTD phosphorylation regulates initiation to elongation

Common MCQ Traps

CSIR NET questions test misconceptions, such as confusing RNA polymerase II with DNA polymerase (which needs primers) or mixing polymerase roles (Pol I for rRNA, Pol III for tRNA/5S rRNA).​

Master these for CSIR NET success in transcription mechanisms.