This chapter deals with the classification of plants and animals. Students get to know that all living organisms are divided into 5 kingdoms namely Monera, Protista, Fungi, Plantae and Animalia. It also describes the classification and evolution, the hierarchy of classification. The classification of life forms is related to their evolution. 2019-2020 DIVERSITY IN LIVING ORGANISMS 97. Plantae and Animalia are further divided into subdivisions on the basis of increasing complexity of body organisation. Plants are divided into five groups: Thallophytes, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms. Animals are divided into ten groups: Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata, Protochordata and Vertebrata. The binomial nomenclature makes for a uniform way of identification of the vast diversity of life around us.