Classification

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At its very simplest level, classification allows us to split every thing into two groups: ‘living things’ and ‘non living things’ (although some may include ‘never lived’ as a third category). The world of living things uses a system of classification to help sort and identify the millions of different organisms of varying complexity and size that there are in the world. At the primary level, it is sufficient to divide living things into two groups, plants and animals, but the full classification system now identifies five major groups or kingdoms. The full classification system is:

 

Kingdom

The largest grouping in classifying living things.

Phylum

The name given to a major group within a kingdom, sometimes called a division.

Class

A class is a major group with a phylum.

Order

An order is a part of a class; some classes are split into many orders.

Family

A large collection of species that have things in common.

Genus

A smaller collection of species that have features in common.

Species

A group of living things that can breed naturally together.

 

The five kingdoms of living things are:

 

Animalia

The animal kingdom contains organisms that feed on plants or other animals. There are between 10 and 20 million species.

Plantae

The plant kingdom contains some 400,000 species of organisms that produce their own food using sunlight.

Fungi

Fungi absorb food made by plants and animals and include mushrooms, toadstools and yeast. There are over 100,000 species.

Monera

This kingdom includes bacteria, the simplest form of life on Earth.  There are some 4,000 species.

Protoctista

This kingdom contains over 65,000 species of simple organisms that mostly have a single cell. Most Protoctista live in water.

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