Where are mrna and ribosomal subunits made?

mRNA is synthesized in the nucleus of eukaryotic cells during the process of transcription, where DNA is used as a template to create messenger RNA. Ribosomal subunits are assembled in the nucleolus, a specialized region within the nucleus, where ribosomal RNA (rRNA) combines with proteins to form the small and large subunits. After assembly, these subunits are transported to the cytoplasm, where they participate in protein synthesis.