Biological Classification — BIOLOGY STD 11 Science — Question

The three kingdom classification system was proposed by Ernst Haeckel in 1866. He did not distinguish bacteria from other living beings. They were incorrectly placed under kingdom-Protista. This shortcoming was removed by Copeland in 1956, when he placed all the bacteria and related organisms into another kingdom-Monera. Copeland's system of classification was able to separate prokaryotic organisms from eukaryotic organisms which was a major drawback of Haeckel's system of classification.