Name

Data Analysis 23 Comparing the Domains

Goal Interpret data to draw conclusions about the classification of organisms.

Skills Focus Interpret Tables, Compare and Contrast

Build Connections Until the twentieth century, classifying life forms was relatively simple. Most biologists classified living things as either plant or animal. Then, in the 1950s, the picture became more complicated as scientists looked more closely. By the 1970s, there were five kingdoms. Four were characterized by eukaryotic cells: plants, animals, fungi, and protists. The bacteria were the one group distinguished by prokaryotic cells. Looking even more closely, scientists realized that a certain group of bacteria had cells that didn’t really fit with bacteria or with the eukaryotes. The five kingdoms were replaced by six kingdoms and three domains. This table compares the three domains and six kingdoms. Use the information in the table to answer the Analyze and Conclude questions on the next page.

Classification of Living Things Domain Bacteria Archaea Eukarya Kingdom Eubacteria Archaebacteria “Protista” Fungi Plantae Animalia Cell type Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote Cell Cell walls with Cell walls Some Cell walls of Cell walls of No cell structures peptidoglycan without cellulose cell chitin cellulose, walls, no peptidoglycan walls; chloroplasts chloroplasts chloroplasts in some Number Unicellular Unicellular Most Most Most Multicellular of cells unicellular; multicellular; multicellular; some some some green multicellular; unicellular algae some colonial unicellular Mode of Autotroph or Autotroph or Autotroph or Heterotroph Autotroph Heterotroph nutrition heterotroph heterotroph heterotroph

Examples Streptococcus, Methanogens, Paramecium, Mushrooms, Mosses, Sponges, Escherichia halophiles amoeba, yeasts ferns, worms, coli giant kelp, flowering insects, slime molds plants fishes, mammals

Analyze and Conclude 1. Interpret Tables Which domain includes four kingdoms? What are those kingdoms?

2. Interpret Tables Which kingdom has cells that lack cell walls?

3. Interpret Tables Which domain includes multicellular organisms?

4. Compare and Contrast How do all members of domain Eukarya differ from all members of domains Archaea and Bacteria?

5. Compare and Contrast On the basis of the information in the table, how are the members of domain Archaea similar to those of domain Bacteria?

Build Science Skills If you were to observe a multicellular organism without cell walls while looking under a microscope, in which domain and kingdom would you classify it? Explain your reasoning.