What Are Merits and Demerits of Two Kingdom Systems?

Merits

1) Plants and animals were divided into two kingdoms not abruptly but based upon specific characters.

2) It initiated systematic methods to classify the living organisms. More and more characters were, later, taken into consideration for development of better methods.

Demerits

1) This system of classification has not dealt upon the status of microorganisms in the living world Example – Viruses, Bacteria. The reason may be the organisms were not properly known by that time.

2) Certain organisms like slime molds and Euglena have characters similar to plants and animals. Slime molds are tiny plants without cell walls whereas Euglena is minute animals with green pigment system. Their position in the living world was, hence, uncertain.

3) The position of the prokaryotes was completely ignored.