Transcription & Translation MCAT Practice Question
A patient presents with mutations in both copies of the POLR2A gene, which encodes the largest subunit of RNA polymerase II. Mutations reduce the enzyme's catalytic activity by 80%. Which aspect of eukaryotic gene expression is most directly impaired?
Answer choices
- ASynthesis of all protein-coding mRNAs and most non-coding RNAs (miRNA, lncRNA precursors)Correct answer
- BProcessing and modification of ribosomal RNA in the nucleolus
- CTranslation initiation at the ribosome start codon
- DNuclear export of mature mRNA through the nuclear pore complex
- EDegradation of mRNA by the nonsense-mediated decay pathway
- FSynthesis of transfer RNA and 5S ribosomal RNA in the nucleolus
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