What Is a Dense Area in a Cell That Contains Nucleic Acids?

The nucleolus is a structure within a cell's nucleus composed of the nucleic acid RNA as well as proteins necessary for the transcription of genetic information to new cells. A cell may contain several nucleoli, although the number is fixed depending on the type of organism. The nucleolus is protected by the nucleus itself, which is encased in a double layer of membrane that separates it from the cell's cytoplasm. The cytoplasm is a liquid inside a cell that contains its organelles and other components necessary for cell function.