Question

which of the following does not occur during rna processing?

adenine nucleotides are added to the end of the rna strand, forming a tail.

segments of rna that do code for the protein are reconnected.

segments of the rna strand that do not actually code for the protein are removed.

a modified guanine nucleotide is added to the beginning of the rna strand as a cap.

mrna attaches to the small subunit of a ribosome.

Explanation:

RNA processing (post - transcriptional modification) includes adding a 5' cap (modified guanine nucleotide), adding a 3' poly - A tail (adenine nucleotides), and splicing (removing introns - non - coding RNA segments and reconnecting exons - coding RNA segments). mRNA attaching to the small ribosomal subunit is part of translation (protein synthesis), not RNA processing.

Answer:

The option "mRNA attaches to the small subunit of a ribosome" does not occur during RNA processing.