Q.Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement taking any two examples.

Biological classification has changed repeatedly as understanding of organisms deepened, and this chapter's own material supplies clear examples.

• Example one: classification systems themselves have evolved — Aristotle first classified organisms using simple morphological characters, Linnaeus later grouped all organisms into just two kingdoms, and Whittaker went on to propose a much more elaborate five-kingdom system based on cell structure, body organisation, nutrition, reproduction and phylogenetic relationships. …

Biological classification has never been fixed; it has been revised repeatedly as biologists learned more about the organisms being classified. This chapter's own material offers two clear examples of that ongoing change.

The first is at the level of entire classification systems. Classification of plants and animals was first proposed by Aristotle, based on simple morphological characters. Linnaeus later classified all living organisms into just two kingdoms, Plantae and Animalia. As understanding grew further, Whittaker proposed a much more elaborate five-kingdom classification — Monera, Protista, Fungi, Plantae and Animalia — judging organisms by cell structure, body organisation, mode of nutrition and reproduction, and phylogenetic relationships. Each step reflects biologists updating the classification as their knowledge deepened. …