AP Biology - Crawford Chapter 20 Viruses, Bacteria and Archaea Mader & Windelspecht 20.1 Viruses, Viroid & Prions 1. List the similarities to living things viruses possess. 2. Why aren’t viruses considered living? Discovery of Viruses 1. Describe the contributions of Pasteur and Ivanowsky to the discovery of viruses. 2. How are viruses classified? 3. Why is it difficult to classify viruses into higher order groups such as phyla? Structure of Viruses 1. How are viruses categorized? a. b. c. 2. Describe the general structure of all viruses. 3. What is an envelope? AP Biology - Crawford 4. How many genes does a typical virus have, compared to a human cell? 5. What else may a virus contain, aside from its genome? 6. Parasitic Nature of Viruses 1. What is an obligate intracellular parasite? 2. What does it mean when a virus is described as host specific? 3. When is it hypothesized that viruses came into existence? 4. How has the rapid mutation of viruses helped them survive? Lytic Cycle 1. Describe the following stages of the lytic cycle: a. Attachment: b. Penetration: c. Biosynthesis: d. Maturation: e. Release: 2. Describe the difference between the lytic and lysogenic cycle: 3. Describe Retroviruses, including their enzymes. AP Biology - Crawford Flu Pandemic 1. What are H and N spikes? 2. When does a flu pandemic occur? 3. Based on how the H5N1 pandemic began, how might have the H1N1 swine flu have been transmitted from animals to humans? 4. What can the codes of the H5N1 and the H1N1 tell you about their structure? 20.2 Prokaryotes 1. What does the term prokaryote mean? 2. What does the prokaryote fossil record indicate? (2 things) 3. Describe the following parts of a typical prokaryote: a. Cell wall b. Glycocalyx i. Capsule ii. Slime layer c. Flagella d. Fimbriae e. Nucleoid f. Plasmids g. Ribosomes 4. Describe the following forms of reproduction is prokaryotes. Distinguish which ones involve genetic recombination: a. Binary fission: b. Conjugation: AP Biology - Crawford c. Transformation d. Transduction 20.3 The Bacteria 1. Distinguish between gram positive and gram negative bacteria. Include the physical differences in each type. 2. Describe the shape of bacteria: a. Spirillum b. Bacilli c. Cocci 3. Describe the following prokaryotic metabolism: a. Obligate anaerobes b. Facultative anaerobes c. Photoautotrophs i. How can autotrophic bacteria exist if they do not have chloroplasts? d. Chemoautotrophs e. Saprotrophs Symbiotic Relationships 1. Describe the following symbiotic relationships involving bacteria: a. Human intestines b. Cows and goats c. Root nodules of soybeans, clover and alfalfa AP Biology - Crawford 2. Describe the commensalistic relationship of bacteria in our intestines. 3. What is an endospore? 4. Describe two human bacterial infections that involve endospores 5. How do most harmful bacteria cause disease? 6. Discuss two ways antibiotics kill bacteria. 7. Construct a hypothesis about how cyanobacteria may have affected the atmosphere of early Earth. 8. Describe a lichen and the relationship between the organisms involved. .