Chapter 19, Problem 7A

Summary Introduction

Introduction:

In the middle of the twentieth century Aristotle recognized only two kingdoms that is Plantae and Animalia. In 1880s Ernst Haeckel added third kingdom that is Protista. Then R. H. Whittaker in 1969 expanded classification system to “five-kingdom system: Protista, Plantae, Monera, Animalia and Fungi on the basis of complexity, cell type and nutrition. Carl Woese along with his colleagues in late 1970s designed two domains that are domain Archaea and domain Bacteria and placed eukaryotes in third domain called Eukarya.