In general, there is one nucleus in each eukaryotic cell, and it contains the genetic material for the cell in the form of chromatin . Prokaryotic cells tend to be small in size. Prokaryotic cells are enclosed by a cell wall made of complex polysaccharides , which are many sugar molecules linked together in a complex way. This polysaccharide wall provides the prokaryotic cell with protection and support. The DNA in prokaryotic cells is usually a long circular molecule, and it is not associated with proteins.
Eukaryotic cells have a nucleus which contains the cellular genes in the form of chromatin.
Chromatin is a complex of DNA and proteins. During mitosis the chromatin forms chromosomes. It contains the genetic information of the cell. Within the nucleus is a nucleolus , whose function it is to produce ribosomes . The nucleolus does not have a membrane around it.