TAILIEUCHUNG - Lecture Biology (6e): Chapter 28 - Campbell, Reece
Chapter 28 - The origins of eukaryotic diversity. This chapter presents the following content: Systematists have split protists into many kingdoms, protists are the most diverse of all eukaryotes. | CHAPTER 28 THE ORIGINS OF EUKARYOTIC DIVERSITY Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Introduction to the Protists 1. Systematists have split protists into many kingdoms 2. Protists are the most diverse of all eukaryotes Protists are eukaryotes and thus are much more complex than the prokaryotes. The first eukaryotes were unicellular. Not only were they the predecessor to the great variety of modern protists, but also to all other eukaryotes - plants, fungi, and animals. The origin of the eukaryotic cell and the emergence of multicellularity unfolded during the evolution of protists. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Eukaryotic fossils date back billion years and “chemical signatures” of eukaryotes date back billion years. For about 2 billion years, eukaryotes consisted of mostly microscopic organisms known by the informal name “protists.” Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings In the five-kingdom system of classification, the eukaryotes were distributed among four kingdoms: Protista, Plantae, Fungi, and Animalia. So far, the plant, fungus, and animal kingdoms are surviving the taxonomic remodeling, though their boundaries have been expanded to include certain groups formerly classified as protists. However, systematists have split protists into many kingdoms. Modern systematists has crumbled the former kingdom of protists beyond repair. 1. Systematists have split protists into many kingdoms Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Protista was defined partly by structural level (mostly unicellular eukaryotes) and partly by exclusion from the definitions of plants, fungi, or animals. However, this created a group including single- celled microscopic members, simple multicellular forms, and complex giants like seaweeds. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin .
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