Answer:
The processing of the 45S rRNA into 5.8S, 18S, and 28S rRNA occurs in the nucleolus of eukaryotic cells. The nucleolus is a specialized structure within the nucleus where ribosomal RNA (rRNA) is synthesized and assembled into ribosomes. The processing of the 45S rRNA transcript involves the removal of internal and external transcribed spacers by specific endonucleases and exonucleases, resulting in the formation of the mature rRNAs. The mature rRNAs are then incorporated into ribosomal subunits, which together with ribosomal proteins, form the functional ribosomes.
Step-by-step explanation: