[Campbell Biology P.405] According to the diagram and accompanying text, which statement bes... | Practice Question
According to the diagram and accompanying text, which statement best explains the importance and specific events of RNA processing in eukaryotes?
A: It involves the removal of exons and joining of introns, occurring in the cytoplasm to prepare mRNA for translation.
B: It modifies the pre-mRNA by adding a 5' cap and a poly-A tail, and splicing out introns, all within the nucleus, before export to the cytoplasm for translation.
C: It is the process where amino acids are added to tRNA molecules in the nucleus, ensuring the correct sequence for protein synthesis.
D: It primarily functions to degrade excess RNA transcripts in the cytoplasm, preventing wasteful protein synthesis.
Explanation
RNA processing in eukaryotes, specifically described in Step 2, involves splicing out non-coding introns and joining coding exons. Additionally, a 5' cap and a poly-A tail are added to the pre-mRNA. These modifications occur in the nucleus and are crucial for the mRNA's stability, transport, and efficient translation.