The Prokaryotic Cell B io F actsheet September 2000 Number 73 1 The contents of this Factsheet cover the relevant AS syllabus content of the major examining boards. By studying this Factsheet the candidate will gain a knowledge and understanding of the structure of a prokaryotic cell, the range of prokaryotic organisms and the importances of prokaryotic organisms. Introduction Bacteria (eg Escherichia coli) and Cyanobacteria (blue-green algae) (eg Nostoc) are single-celled and characteristically possess no nucleus. They are prokaryotic organisms. Remember ? the Cyanophyta or blue-green algae are now classed as Cyanobacteria because they are prokaryotic. Algae are all eukaryotic since they possess nucleated cells and cell organelles. In some older