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Chapter 10 Section 1 Bacteria and Archaea Bellringer What are the two kingdoms of bacteria? What are three shapes of bacteria? Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Objectives • Describe the characteristics of prokaryotes. • Explain how prokaryotes reproduce. • Relate the characteristics of archaea. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Some Characteristics of Bacteria and Archaea • The domains Bacteria and Archaea consists of single-celled organisms. These two domains consist of the oldest forms of life on Earth. • The Shape of Bacteria Bacilli are rod shaped. Cocci are spherical. Spirilla are long and spiral shaped. Each shape helps bacteria in a different way. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Some Characteristics of Bacteria and Archaea, continued • No Nucleus! All bacteria and archaea are singlecelled organisms that do not have a nucleus. An organism that does not have a nucleus is called a prokaryote. • Prokaryote Reproduction Prokaryotes reproduce by a process called binary fission, in which one single-celled organism splits into two single-celled organisms. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Some Characteristics of Bacteria and Archaea • Endospores contain genetic material and proteins and is covered by a thick, protective coat. Some bacteria become inactive and form endospores in poor environmental conditions. • When conditions improve, the endospores break open and the bacteria become active again. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea The Domain Bacteria • The domain Bacteria has more individuals than all other domains combined do. • Classification of Bacteria Bacteria are classified by the way they get food. Most bacteria are consumers. • Cyanobacteria are producers. Cyanobacteria usually live in water and contain the green pigment chlorophyll. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea The Domain Archaea • The three main types of archaea are heat lovers, salt lovers, and methane makers. • Harsh Environments Archaea often live where nothing else can. Most archaea prefer environments where there is little or no oxygen. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 10 Section 1 Bacteria and Archaea Alternative reproduction • Sometimes bacteria gain secondary circles of DNA called plasmids. • Plasmids usually code for just one gene. • Bacteria can fuse together briefly and transfer plasmids. This is called conjugation. • This is one way bacteria pass on antibiotic resistance. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.