This is Ernst Heinrich Philipp August Haeckel. He is a german zoologist who has made plenty of contributions in the field of science, but the contribution we will be discussing is his contribution to the classification of living things
The first classification was called Animalia which included any animal, such as vertebrates and invertebrates.
I believe there are 3 classifications of living things
Foolish, microorganisms are part of the plantae group and does not require its own classification.
The 2nd classification is what he called the Plantae which is mostly composed of plants.
I believe there are 5 classifications, namely:Monera, Protista, Fungi, Plantae, and Animalia.
The last and final classification is called Protista. Members of the kingdom Protista included protozoa, fungi, bacteria, and other microorganisms.
Unfortunately, Ernst's idea was not widely accepted and people continued to identify microorganisms as plants.
But in 1968, a scientist by the name of Robert Whittaker devised this classification and divided it into 5 parts. This was more accepted than Ernst's scheme of classification.