In an animal cell, what does the nucleus do?

A 'true' nucleus is present in all eukaryotic cells except in mature RBCs. It is largest cell organelle and can be seen under light-microscope. Normally, spherical in shape but in some cells it may be polymorphic, e.g. in WBCs, nucleus is bilobed or multilobed. read more

The nucleus contains a center called the nucleolus, which is a spherical structure that assembles the ribosomes, the protein-making factories of the cell. The nucleolus also produces the various types of RNA, the molecules that help synthesize proteins from DNA. read more