What is the function of the nucleolus within the nucleus?

The nucleolus is a prominent structure found within the nucleus of eukaryotic cells and plays a critical role in the synthesis of ribosomes. It is primarily responsible for the production and processing of ribosomal RNA (rRNA), which is a key component of ribosomes, the cellular machinery required for protein synthesis. The nucleolus assembles rRNA molecules with ribosomal proteins to form the subunits that eventually exit the nucleus and come together in the cytoplasm to create functional ribosomes.

Ribosomes are essential for translating messenger RNA (mRNA) into proteins, an important process for cell function and growth. Thus, the nucleolus's main function relates directly to the formation of ribosomes, making this answer correct within the context of its role in cellular biology.