• Five kingdom classification
• Merits of five kingdom classification
• Demerits of five kingdom classification

Five Kingdom Classification - Monera, Protista, Fungi, Plantae, Animalia:

1. Two kingdom classifications: Carolus Linnaeus in 1758 classified the living organisms into two groups as plants and animals.
   
   
2. Five kingdom classification: H. Whittaker in 1959 further classified the organisms into five kingdoms as Kingdom Monera, Kingdom Protista, Kingdom Fungi, Kingdom Plantae, and kingdom Animalia.

The five kingdoms and their key characteristics are given below:

1. Monera:

• These are prokaryotes; which means nuclear materials are not membrane-bound in them.

• They may or may not have a cell wall.

• They can be autotrophic or heterotrophic.

• All organisms of this kingdom are unicellular.

• Examples: Bacteria, blue-green algae (cyanobacteria), and mycoplasma.

2. Protista:

• These are eukaryotes and unicellular.

• Some organisms use cilia or flagella for locomotion.

• They can be autotrophic or heterotrophic.

• Examples: Plants like unicellular algae, diatoms; animals like protozoans (Amoeba, Paramecium, Euglena)

3. Fungi:

• These are eukaryotic organisms with the cell walls, made up of Chitin. They do not perform Photosynthesis (Heterotrophs).

• They may be unicellular (yeast) or filamentous (most fungi).

• They feed on decaying organic materials. Such a mode of nutrition is called saprophytic. Some fungi live in a symbiotic relationship with other organisms (Lichens), while some are parasites as well.

• Examples: Mushrooms(Agaricus), green mold(Penicillium), smut (Aspergilus).

4. Plantae:

• These are multicellular and autotrophs.

• The presence of chlorophyll is a distinct characteristic of plants, because of which they are capable of taking out photosynthesis.

• Cell wall is present.

5. Animalia:

• These are eukaryotic, multicellular, and heterotrophic organisms.

• Cell wall is absent.

Hierarchy Classification- Formation of Kingdoms:

Linnaeus proposed a classification system by arranging organisms into taxonomic groups at different levels according to the characteristics they have. The groups or the levels from top to bottom are:

Five Kingdom Classification - Monera, Protista, Fungi, Plantae, Animalia:

1. Monera

2. Protista

3. Fungi

4. Plantae

5. Animalia

The five kingdoms and their key characteristics are given below:

1) Monera:

• Woese divided Monera into Archaebacteria and Eubacteria.

• Prokaryote

• Unicellular

• Cell wall may be present or absent

• Can be Autotrophs or heterotrophs

• Eg. bacteria, blue-green algae or cyanobacteria, and mycoplasma

2) Protista:

• Eukaryote

• Unicellular

• Can be autotrophic or heterotrophic

• Uses hair-like cilia or whip-like flagella for movement

• diatoms and protozoans like an amoeba, euglena, paramecium, etc.

3) Fungi:

• Eukaryote

• Unicellular or multicellular (at certain stages of life)

• Saprophytes- feed on dead and decayed matter

• Cell-walls made of a tough complex sugar called chitin.

• Symbiosis: lichens are symbiotic life forms of fungi and algae.

• Lichens: They are bioindicators of pollution i.e. they don’t grow on places with pollution.

• eg. Agaricus (mushrooms), Penicillium, Aspergillus

4. Plantae:

• These are multicellular and autotrophs.

• The presence of chlorophyll is a distinct characteristic of plants, because of which they are capable of taking out photosynthesis.

• Cell wall is present.

5. Animalia:

• These are eukaryotic, multicellular, and heterotrophic organisms.

• Cell wall is absent.

The hierarchy of classification:

Ernst Haeckel (1894), Robert Whittaker (1959), and Carl Woese (1977) have tried to classify all living organisms into broad categories, called kingdoms.

Further classification is done by naming the sub-groups at various levels as given in the following scheme:

• Kingdom

• Phylum (for animals) / Division (for plants)

• Class

• Order

• Family

• Genus

• Species