Kingdoms and Domains Section 18 3 Objectives 9

Kingdoms and Domains Section 18 -3 Objectives: 9. 0 Differentiate between the previous fivekingdom and current six-kingdom classification systems. 9. 1 Sequencing taxa from most inclusive to least inclusive in the classification of living things

Expansion of the “Tree of Life” (1950’s) How many kingdoms did Linnaeus name? What were they? Scientists soon realized microorganisms, such as protists and bacteria, did not belong in either of those two kingdoms, so a 3 rd kingdom was created --- Protista. (Late 1800’s) Next, Fungi: mushrooms, yeasts, and molds Monera: bacteria and other prokaryotes

Six Kingdoms (1990’s) Noted differences among members of the Monera kingdom led to dividing it into two kingdoms: Eubacteria and Archaebacteria. Six Kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia

Three Domains Classification System Based on comparative studies of a small subunit of ribosomal RNA that occurs in all living things. Three domains: 1. Bacteria 2. Archaea 3. Eukarya What organisms do you think these domains include?

Domain Bacteria Unicellular Prokaryotes Cell walls contain peptidoglycan. Corresponds to kingdom _____.

Domain Archaea Unicellular Prokaryotic Live in Earth’s most extreme environments Cell membranes contain lipids not found in any other organisms Correspond to kingdom _____.

Domain Eukarya Contains ALL organisms that have a nucleus! What kingdoms would be included? We can identify members of the kingdoms Animalia, Plantae, and Fungi. Kingdom Protista includes organisms with a nucleus, but that cannot be classified as fungi, plants, or animals. has the greatest variety of organisms.

Examining Diagrams and Tables Figures 18 -11 and 18 -12 summarize characteristics of kingdoms and domains. Figure 18 -13: What type of diagram does this look like? What do you think the big circle with a “? ” in it means?