Taxonomy and Biodiversity

Identification of Organisms

• Organisms are identified based on their characters.
• Maximum similarity: Similar characters decrease from bottom to top.

About Taxonomy

• Taxonomy and Systematics:
  • Taxonomy: Classification of organisms.
  • Systematics: Study of the evolutionary history of organisms.

Biodiversity

• Biodiversity means: Distribution of plants, animals, and microorganisms on Earth.
• 1.7-1.8 million species have been discovered so far.
• Local names depend on regional languages.
• Scientific names are necessary so that there is only one name everywhere.

Nomenclature

• Identification of an organism is necessary before naming it.
• There are certain standards and rules in nomenclature.
  • The International Code for Botanical Nomenclature (ICBN) and the International Code of Zoological Nomenclature (ICZN) are followed.

Binomial Nomenclature

• Established by Linnaeus.
• Every organism has a scientific name consisting of two words:
  • First word: Genus
  • Second word: Species
• Scientific names are in Latin and written in italics.

Taxonomic Category

• Classification into different categories:
  • Kingdom
  • Phylum (or Division)
  • Class
  • Order
  • Family
  • Genus
  • Species
• Kingdom is the largest and species is the smallest unit.

Species and Genus

• Species: The smallest unit.
• Genus: A group of species.
• Related species are placed in the same genus.

Family

• Made from a group of genera.
• Related genera are placed in a family.

Order

• Made from a group of families.
• Related families are placed in an order.

Class and Phylum

• Different orders together form a class.
• A phylum is formed from several classes.

Kingdom

• A kingdom is a group of various phyla.
• There is separate nomenclature for animals and plants.

Important Points

• The amount of similar characters decreases as we move from species to kingdom.
• Greater similarity is at lower levels, such as species and genus.
• The process of classification becomes simple when there are more similar characters.

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These notes succinctly present the important aspects of taxonomy, biodiversity, and the classification of organisms.