The nucleolus of a cell is part of the production of ribosomes and contains the cell's RNA, one of the vital building blocks that tells the cell what it is. Ribosomes generate proteins that are needed for the basic functions of living cells. Cells have a roughly spherical shape, which coincides with the rounded shape of the nucleolus.
Thanks to the presence of a nucleolus, cells can generate and interact with proteins that help them generate more cells and perform other complex tasks. Proteins are large biological molecules and are part of the process of replicating DNA, making them vital in creating the building blocks of life.
Nucleoli are found only in eukaryotic cells and are a vital part of the entire structure. The structure of this cell component was first theorized properly in 1964 when studies of a species of frog yielded insightful results. Experts discovered that cells that lacked a nucleolus in their structure were not capable of life in the case of these frog eggs. Only the cells that contained a nucleolus seemed to be able to produce the necessary components to ultimately grow into a healthy new frog. The scientists who discovered this were John Gurdon and Donald Brown.