Which part of the nucleus is responsible for assembling ribosomes?

• A. Nucleus
• B. Nucleolus
• C. Chromatin
• D. Nuclear Membrane

Answer: (B)

The main idea is that ribosome assembly happens in a specific region inside the nucleus called the nucleolus. This area is where ribosomal RNA is made and combined with proteins to form the small and large ribosomal subunits. Once those subunits are assembled, they’re sent out to the cytoplasm to join together into functional ribosomes that translate genetic information into proteins. The whole nucleus houses DNA and controls cell activities, chromatin is the DNA–protein material that forms chromosomes, and the nuclear membrane is just the envelope around the nucleus—these aren’t the sites where ribosome subunits are assembled.