Chapter 19 Bacteria and Viruses Chapter Test A Multiple Choice Write the letter that best answers the question or completes the statement on the line provided. 1. Prokaryotes are single-celled organisms that lack a a. cell wall. c. definite shape. b. cell membrane. d. nucleus. 2. The structure labeled C in Figure 19-1 is a. DNA. c. the nucleus b. an organelle. d. a high-energy sugar. 3. Which of the following statements is NOT true about archaebacteria? a. They are thought to be ancestors of eukaryotes. Figure 19-1 b. Many live in harsh environments. c. They lack peptidoglycan in their cell wall. d. They make up the largest kingdom of prokaryotes. 4. Spherical prokaryotes are called a. spirilla. c. cocci. b. flagella. d. bacilli. 5. When treated with Gram stain, Gram-positive bacteria appear a. violet. c. yellow. b. pink. d. orange. 6. Unlike photoautotrophs, chemoautotrophs obtain energy a. directly from the sun. b. directly from chemical reactions. c. indirectly from carbon molecules. d. indirectly from other organisms. 7. Which of the following describes a role of bacteria in the environment? a. carrying out photosynthesis b. recycling nutrients c. fixing nitrogen d. all of the above 8. Humans use bacteria in all of the following ways EXCEPT to a. clean up small oil spills. b. make butter and milk. c. mine minerals from the ground. d. synthesize drugs. D A B C Chapter 19 Test A 237
9. What is the basic structure of a virus? a. DNA or RNA surrounded by a protein coat b. a capsid surrounded by a protein coat c. a tail sheath surrounded by tail fibers d. a tiny cell surrounded by a cell wall 10. Bacteriophages infect a. other viruses. c. any available host cell. b. bacteria only. d. cells undergoing the lytic cycle. 11. Viruses that contain RNA as their genetic information are called a. prophages. c. retroviruses. b. bacteriophages. d. capsids. 12. What did French chemist Louis Pasteur help establish? a. that lytic infections involved cell bursting b. that bacteria were responsible for some diseases c. that antibiotics were effective against bacteria d. that viral diseases disrupt the body s equilibrium 13. What can a vaccine do when it is injected into the body? a. prompt the body to produce immunity to a disease b. produce toxins that disrupt bacterial equilibrium c. use bacterial cells for food d. destroy new pathogens as they arise in the body 14. Which of the following diseases is NOT caused by a virus? a. tetanus c. AIDS b. influenza d. chickenpox 15. Which of the following is NOT true about prions? a. They are particles composed only of protein. b. They are single-stranded RNA molecules with no capsid. c. They can cause disease in humans. d. They contain no RNA or DNA. Completion Complete each statement on the line provided. A Figure 19-2 B C 16. The organism labeled A in Figure 19-2 is an example of a(an). 17. The knoblike root nodules of soybean plants are the sites of. 238 Chapter 19 Test A
18. In a lysogenic infection, the viral DNA that is embedded in a host cell s DNA is called a(an). A C 19. In Figure 19-3, the structure labeled D is a(an). 20. The structure labeled B in Figure 19-3 is the. Short Answer In complete sentences, write the answers to the questions on the lines provided. B Figure 19-3 D 21. List four factors that are used to identify prokaryotes. 22. Describe two roles that bacteria have in the environment. 23. What is a virus? Describe the basic structure of a virus. 24. Why are viruses not considered to be living things? 25. List three methods used to control bacterial growth. Chapter 19 Test A 239
Using Science Skills Use the diagram below to answer the following questions on the lines provided. A student placed a disk of filter paper in each of the following solutions: disinfectant 1, disinfectant 2, disinfectant 3, and distilled water. While the four disks were soaking in their respective solutions, she streaked a sterile nutrient agar dish with a culture of E. coli bacteria. Then, she placed each disk carefully onto the nutrient agar dish, placed the lid on the dish, taped it shut, and incubated the dish at 37ºC for several days. Figure 19-4 shows how the nutrient agar dish looked on Day 1 and Day 4. DAY 1 DAY 4 in disinfectant 2 in disinfectant 1 in disinfectant 1 in disinfectant 2 in disinfectant 3 in distilled water in disinfectant 3 in distilled water Figure 19-4 26. Designing Experiments Based on Figure 19-4, what is the student probably trying to test? 27. Controlling Variables What is the control in the experiment shown in Figure 19-4? 28. Drawing Conclusions How can the student measure the effectiveness of each disinfectant shown in Figure 19-4? 240 Chapter 19 Test A
29. Inferring Look at the dishes in Figure 19-4. Which disinfectant was the most effective at controlling the growth of E. coli? How do you know? 30. Drawing Conclusions Look at the results of the experiment shown in Figure 19-4. Why do you think the different disinfectants are not equally effective against the E. coli bacteria? Essay Write the answer to each question in the space provided. 31. Explain how the two groups of prokaryotes differ. 32. What is the difference between binary fission and conjugation? Chapter 19 Test A 241
33. Briefly describe two ways that bacteriophages infect cells. 34. Explain how bacteria cause disease. Give an example of each method. 35. Contrast a bacterial disease with a viral disease. 242 Chapter 19 Test A