The nucleolus is a spherical body inside the nucleus, not bounded by a membrane. It is the site of active synthesis of ribosomal RNA (rRNA). The rRNA combines with ribosomal proteins (imported from the cytoplasm) to form the ribosomal subunits. These subunits then pass out through the nuclear pores into the cytoplasm, where they assemble into functional ribosomes. So ribosomes are produced in the nucleolus.
ConceptNucleolus as site of ribosome synthesis
Cell: The Unit of Life in past papers
137 questions from this chapter have appeared across 27 exam years.
