Other
Panhandle Area Educational Consortium: The Six Kingdoms of Life [Pdf]
Scientists look at the evolutionary history of organisms to divide them into kingdoms. For awhile, there has been 5 kingdoms, but many scientist are now using 6 kingdoms.
Other
Alternative Classifications of Life
The Linnaean system (1758) classified all macroscopic living organisms as either Animals or Plants, based on whether they moved [anima, with a soul] or not. Thus, Fungi were included as plants. With the invention of the microscope and...
BiologyWise
Biology Wise: Types of Protists
Explains what types of organisms are in the kingdom Protista and describes the different types of protists in five broad categories and in their sub-categories.