LEVELS OF ORGANISATION. The level of classification is called taxon. Plural –taxa. A taxon is a unit of classification made of similar organisms. The largest taxon is the kingdom and the smallest taxon is the species. All organisms have been put in seven major taxa and these include:

  1. Kingdom
  2. Phylum (phyla)
  3. Class
  4. Order
  5. Family
  6. Genus (genera)
  7. Species
  8. https://www.google.com/

Easy formula for seven taxa from highest to lowest



A kingdom is the largest taxon, and all the other taxa (groups ofliving organisms) are placed in one the kingdoms. In modern classification system, there are 5 kingdoms:

  1. 1.Monera (bacteria)
  2. Protoctista
  3. Fungi (Mycota)
  4. Plantae
  5. Animalia

Note:Viruses are not classified in any of the five kingdoms because they do not haveall the characteristics of all living things. For example;

  • They do not have cellular structures like cytoplasm, organelles.
  • They use nuclear material and organelles of other living organisms to carry out their metabolic processes.
  • They can survive out their host’s cell as inert organic crystal


A species is the smallest taxon which is made up of individuals that have almost the same characteristic features and can interbreed freely to produce viable off springs i.e. reproductively fertile offsprings

Examples of hierarchy system of classification


Binomial system of nomenclature:

Binomial nomenclature is the system of giving a scientific name to an organism.The word binomial comes from two words bi-meaning two and nomial meaning name.The first accepted classification and nomenclature was introduced by a Swedish scientist called Carl Linnaeus (1707 -1778).

Rules of binomial system of nomenclature

  • Each organism should be given two Latin or Greek names which include generic (genus) name followed by specific (species) name.
  • The generic name should start with a capital letter and a specific name starts with the small letter
  • When written both names should be underlined separately or printed in italics

Examples of some scientific name for common organisms

Human –scientific name is Homo sapiensMaize –scientific name is Zea mays

Assignment: write the scientific names of the following; honey bee, meadow mushroom and house fly.

Importance of classification

  • It is easy to study organism in a group since the members of a specific group resemble.
  • It helps new organisms to be easily classified since they share certain characteristics with those in existence.
  • It helps the scientist to easily identify organisms belonging to the same group.
  • The use of scientific names enables to prevent confusion that would arise if the organism had different names used in different place