The nucleus and nucleolus are running for president and vice president of the cell. The nucleus is described as the brain and leader of the cell, containing the DNA and directing major cellular activities. The DNA in the nucleus allows for protein synthesis. The nucleolus is the largest organelle in the nucleus and acts as the ribosome factory, regulating protein and cellular functions. It has a dense fibrilla component, fibrilla centers, and granular components that make up its structure.