1. The Earth inhibited by millions organisms of different species.Many organisms are not found yet and identified their species
2. Local name for an organism is not the same based on the regions and countries
3. Hence,a scientific method of classification and nomenclature is required to ease research and communication as well as for reference at international level
4. In the current classification system,all identified organisms are classified into six Kingdom

The hierarchy classification system is used to classify organisms into seven main groups based on levels:

1. Kingdom: The largest group which containing all the organisms in a particular Kingdom
2. Phylum: The second large group which containing some of the organisms from a particular Kingdom.Organisms in the same phylum share the common characteristics
3. Class
4. Order
5. Family
6. Genus
7. Species: The most specific hierarchy of classification

Linnaecus Binomial System:

• Scientific method
• In italics or underlined separately

Two Latin names:

• The first name is genus and starts with a capital letter
• The name given is based on genetic relation
• The second name is species and starts with a small letter
• The name given is based on scientist name ,place of discovery and characteristics

Methods used to construct a dichotomous key:

• Determine a particular characteristics which can classify a group of organisms into two categories
• Divide the organisms of the same category into another two categories until each organism is identified
• The number of steps required to classify organisms is the number of organisms (m) required to be identified minus one, that is m-1