name the three field of syatematics?

give the two name system of organisms?

Trinomial Nomenclature:

In biology, trinomial nomenclature is used to name subspecies. It is proposed by Huxley and Stricklandt. Trinomial nomenclature refers to "three-part description" that is each name has three parts.

• The first part is the genus name,
• The second part is the species name
• The third part is the subspecies name.

In Trinomial Nomenclature, the subspecies is of a lower category than the species. When members of any species have large variations then trinomial system is used.

Example: 

In Animals:

The species of crow is named as Corvus splendora – Indian Crow.  It has three subspecies named as follows.

• Corvus splendens insolens - It is a Myanmar Crow.
• Corves spelendens protegatus  - It is a Srilanka Crow.

In Plants:

• Brassica oleracea var. botrytis  - Cauliflower
• Brassica oleracea var. capitata  - Cabbage
• Brassica oleracea var. caulorapa  - Knol-Khol

Binomial Nomenclature:

• System of giving two names to an organism is called Binomial nomenclature. It is recognized all over the world.
• Corolus Linnaeus gave a scientific naming system in which an organism is given two names.
• The first part is the generic name and the second part is the (specific) species name.

Conventions that are followed:

• It is conventional to write the first letter of the generic name with a capital and the first letter of the specific name with a small letter. Felis domestica – common cat.
• Scientific names must be underlined separately when written by hand.
• In printed matter these names are printed in Italic or in Bold type.

Uses:

• Scientific names are followed and understood all over the world
• Names are not changed according to country or language
• Names are not changed often.