The primary characteristic on which the broad division of organisms is made is the nature of cell.
On the basis of nature of cell, organisms are broadly divided into two types :-
1. Prokaryotic organisms
2. Eukaryotic organisms
Prokaryotic organisms do not have a well defined nucleus and membrane bound organelles, and thus these organisms having prokaryotic cells cannot perform complex metabolisms.
Eukaryotic organisms have a well defined nucleus and membrane bound organelles, and thus these organisms having eukaryotic cells can perform complex metabolisms.