As we all know that cell is the basic unit of organisation in all living organisms of the universe. These organisms on the basis of their cell characters are broadly classified as:
A. Prokaryotes: The term Prokaryotes is the combination of two words i.e., “pro” means primitive and “karyon” means nucleus. The group is characterised by the lack of nucleus and any membrane bound organelles. Prokaryotes include Bacteria, Cyanobacteria and Archaea.
B. Eukaryotes: In contrast to prokaryotes, eukaryotes (“eu” means true) exhibit a complex structural organisation comprising membrane bound organelles such as nucleus, plastids, mitochondria, golgi body, endoplasmic reticulum, lysosomes etc. Additionally the cells of eukaryotes are much larger than prokaryotes. This group mainly includes plants, fungi, protists and animals.