《拯救我的托福話題英語：拯救我的托福話題英語（自然篇）》：
　　Classifi cation of Living Organisms 
　　With an estimated 10 million to 13 millionspecies on Earth， the diversity of life isimmense.
　　Since the dawn of civilization， there havebeen many attempts to classify livingorganisms.
　　Greek philosopher Aristotle grouped lifeforms as either plant or animal.
　　He was far ahead of his time in separatinginvertebrate animals into differentgroups and was aware that whales anddolphins had mammalian charactersand were not fi sh.
　　Lacking the microscope， he could notdeal with microscopic organisms.
　　Usually regarded as the founder ofmodern taxonomy， Carolus Linnaeusis most famous for creating a system ofnaming plants and animals.
　　Classifi cation of organisms into plants andanimals was easily done and was easy tounderstand， however， a large number oforganisms did not fall into either category.
　　In 1969， Whittaker proposed a FiveKingdom Classifi cation.
　　The kingdoms defi ned by him areKingdom Monera， Kingdom Protista，Kingdom Fungi， Kingdom Plantae， andKingdom Animalia.
　　In the Five Kingdom Classifi cation ofWhittaker， there is no mention of someacellular organisms like viruses and viroids.
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