Learning Objectives:

• Learns the importance of the living world and its diversity
• Understands the need for classification - Creates an interest in systematics and understands the importance of taxonomy foR classification of animals
• Knows the key rules of nomenclatures and their uses

All living forms co-exist with each ­other. There are about 8.7 million ­species of organisms have been estimated to exist on earth. A study r­ eports that 86% of all species on the land and 91% of those in the seas are yet to be discovered, described and catalogued. Though humans are placed in the top most position on the hierarchy, they have to depend on plants and animals for food. Animals are also used as source of labour, in farming, as pets, and for o ­ ther ­economic benefits. Understanding ­animals and their unique c­ haracteristics, habitats, ­behaviour and evolutionary ­relationships is very ­ important. This chapter deals with, diversity in the ­living world, need for classification, types of classification, ­taxonomical hierarchy, nomenclature and tools for studying taxonomy.