Kingdoms

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Prokaryotes Vs. Eukaryotes
Five Kingdom Classification
Advantages of the Five Kingdom Classification
Disadvantages of the Five Kingdom Classification
Summary

Carolus Linnaeus placed all living organisms into two kingdoms; Plantae and Animalia. The two-kingdom classification was later found to be inadequate because it places organisms with a true nucleus (eukaryotes) with those without a true nucleus (prokaryotes).

Prokaryotes Vs. Eukaryotes

	Prokaryotes:	Eukaryotes:
1.	No distinct nucleus.	Distinct nucleus present.
2.	No nuclear membrane.	Nuclear membrane present.
3.	Nuclear materials scattered on the cytoplasm.	Nuclear materials not scattered on the cytoplasm.
4.	No membrane-bounded organelles.	Membrane bounded organelles present.
5.	Exist only in simple forms.	Exist in complex forms.
6.	They are primitive.	They are more advanced.
7.	Bacteria and blue-green algae are examples of prokaryotic cells.	Fungi, plant and animal cells are examples of eukaryotic cells.

Green photosynthetic plants were also placed with non-green plants.

Under the basis of the difference between eukaryotes and prokaryotes cells, as well as the mode of nutrition, scientist R.H Whittaker proposed the five kingdom classification, in 1969.

Biologists now favour classifying organisms using the five-kingdom classification.

The five kingdoms are;

Monera
Protista
Fungi
Plantae
Animalia

The prokaryotes were placed under the Kingdom Monera while the eukaryotes were classified under four kingdoms: Protista, Plantae, Fungi & Animalia.

The five kingdom way of classifying living organisms still presents problems as some organisms such as lichen and viruses do not fit into any of these kingdoms. Viruses are not included in the five-kingdom classification because they do not have a cell structure and cannot reproduce, so they are currently not considered living things. However, there are still debates going on, as some scientists are of the opinion that they are in fact living things.

Advantages of the Five Kingdom Classification:

When compared to the two-kingdom classification, it is better and more natural.

It separates unicellular and multicellular organisms.

It separates autotrophs and heterotrophsA heterotroph is an organism that consumes other organisms in a food chain. The term stems from the Greek words hetero for “other” and trophe for “nourishment.” More.