1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F5 on the top row of your keyboard. To advance to the next slide click the left mouse button once. From the Chapter screen you can click on any section to go directly to that section’s presentation. Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. You may exit the slide show at any time by pressing the Esc key. How to Use This Presentation

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter Presentation Transparencies Image and Math Focus Bank Bellringers Standardized Test Prep CNN Videos Visual Concepts Resources

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Table of Contents Section 1 Disease Section 2 Your Body’s Defenses Chapter 27 Body Defenses and Disease

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Bellringer Brainstorm as many different names of diseases as you can. Don’t forget to list both physical illnesses and mental illnesses. How do you think people get these diseases? Record your answers in your science journal. Chapter 27

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Objectives Explain the difference between infectious diseases and noninfectious disease. Identify five ways that you might come into contact with a pathogen. Discuss four methods that have helped reduce the spread of disease. Chapter 27

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Causes of Disease Some diseases, such as most cancers and heart disease, are not spread from one person to another. They are called noninfectious diseases. A disease that can be passed from one living thing to another is an infectious disease. Infectious diseases are caused by agents called pathogens. Chapter 27

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Pathways to Pathogens Air Some pathogens travel through the air, such as when someone sneezes. Contaminated Objects Drinking glasses, doorknobs, keyboards, combs, and towels that have been used by an infected person can all pass pathogens. Chapter 27

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Pathways to Pathogens, continued Person to Person You can become infected with some illnesses by kissing, shaking hands, or touching the sores of an infected person. Animals Some pathogens are carried by animals. Food and Water Bacteria growing in foods and beverages can cause illness. Chapter 27

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Disease Putting Pathogens in Their Place Chapter 27 Pasteurization The method of using heat to kill bacteria is called pasteurization. Vaccines and Immunity The ability to resist or recover from an infectious disease is called immunity. A vaccine is a substance that helps your body develop immunity to a disease. Antibiotics An antibiotic is a substance that can kill bacteria or slow the growth of bacteria.

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Bellringer Make a list in your science journal of all the different ways pathogens might enter the body. Is there anything that you do to avoid getting sick? Do you know of anything that your body automatically does to get rid of pathogens? Chapter 27

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Objectives Describe how your body keeps out pathogens. Explain how the immune system fights infections. Describe four challenges to the immune system. Chapter 27

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses First Lines of Defense Your skin is made of many layers of flat cells. The outermost layers are dead. As a result, many pathogens that land on your skin have difficulty finding a live cell to infect. Chapter 27

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Failure of First Lines Sometimes, skin is cut or punctured and pathogens can enter the body. Cell parts in the blood called platelets help seal the open wound so that no more pathogens can enter. The cells and tissues that recognize and attack foreign substances in the body belong to the immune system. Chapter 27

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Cells of the Immune System Macrophages engulf and digest many microorganisms or viruses that enter your body. T cells coordinate the immune system and attack many infected cells. B cells are immune-system cells that make antibodies. Antibodies are proteins that attach to specific antigens. Chapter 27

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu ResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Responding to a Virus If virus particles enter your body, some of the particles may pass into body cells and begin to replicate. Other virus particles will be engulfed and broken up by macrophages. This is just the beginning of the immune response. Chapter 27

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu ResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu ResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Fevers A moderate fever of one or two degrees actually helps you get well faster because it slows the growth of some pathogens. A fever also helps B cells and T cells multiply faster. Chapter 27

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27 Memory Cells Memory B cells are cells in your immune system that “remember” how to make an antibody for a particular pathogen. If the pathogen shows up again, the memory B cells produce B cells that make enough antibodies in just 3 or 4 days to protect you.

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Primary and Secondary Immune Response Chapter 27 Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Challenges to the Immune System Allergies happen when the immune system overreacts to antigens that are not dangerous to the body. Autoimmune Disease is a disease in which the immune system attacks the body’s own cells. In an autoimmune disease, immune-system cells mistake body cells for pathogens. Chapter 27

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Challenges to the Immune System, continued Cancer is a disease in which the cells begin dividing at an uncontrolled rate and become invasive. AIDS The human immunodeficiency virus (HIV) causes acquired immune deficiency syndrome (AIDS). HIV infects the immune system itself, using helper T cells as factories to produce more viruses. Chapter 27

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Body Defenses and Disease Concept Map Use the terms below to complete the concept map on the next slide. Chapter 27 hemophilia pathogens immune system fungi viruses protists infectious diseases noninfectious diseases

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu ResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menu Concept Map Chapter 27

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu ResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menuResourcesChapter menu Concept Map Chapter 27

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu End of Chapter 27 Show

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu CNN Videos Scientists in Action: In Search of Nature’s Cures Scientists in Action: In Search of Nature’s Cures Science, Technology, and Society: Computer Healing Science, Technology, and Society: Computer Healing Body Defenses and Disease Chapter 27

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Read each of the passages. Then, answer the questions that follow each passage. Chapter 27 Standardized Test Preparation

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1 Bacteria are becoming resistant to many human-made antibiotics, which means that the drugs no longer affect the bacteria. Scientists now face the challenge of developing new antibiotics that can overcome the resistant strains of bacteria. Antibiotics from animals are different from some human-made antibiotics. Continued on the next slide Chapter 27 Standardized Test Preparation

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1, continued These antibiotics bore holes through the membranes that surround bacterial cells, causing the cells to disintegrate and die. Bacterial membranes don’t mutate often, so they are less likely to become resistant to the animal antibiotics. Chapter 27 Standardized Test Preparation

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. In this passage, what does mutate mean? A to change B to grow C to form D to degrade Chapter 27 Standardized Test Preparation

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. In this passage, what does mutate mean? A to change B to grow C to form D to degrade Chapter 27 Standardized Test Preparation

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Based on the passage, which of the following statements is a fact? F Bacterial membranes are on the inside of the bacterial cell. G Bacterial membranes are on the outside of the bacterial cell. H All strains of bacteria mutate. I Bacterial membranes never change. Chapter 27 Standardized Test Preparation

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Based on the passage, which of the following statements is a fact? F Bacterial membranes are on the inside of the bacterial cell. G Bacterial membranes are on the outside of the bacterial cell. H All strains of bacteria mutate. I Bacterial membranes never change. Chapter 27 Standardized Test Preparation

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Based on the passage, which of the following sentences is false? A Antibiotics from animals are different from human- made antibiotics. B Antibiotics from animals bore holes in bacterial membranes. C Bacterial membranes don’t change very often. D Bacteria rarely develop resistance to human-made antibiotics. Chapter 27 Standardized Test Preparation

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Based on the passage, which of the following sentences is false? A Antibiotics from animals are different from human- made antibiotics. B Antibiotics from animals bore holes in bacterial membranes. C Bacterial membranes don’t change very often. D Bacteria rarely develop resistance to human-made antibiotics. Chapter 27 Standardized Test Preparation

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2 Drinking water in the United States is generally safe, but water lines can break, or treatment plants can become flooded, allowing microorganisms to enter the public water supply. Bacteria growing in foods and beverages can cause illness, too. Continued on the next slide Chapter 27 Standardized Test Preparation

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2, continued Refrigerating foods can slow the growth of many of these pathogens, but meat, fish, and eggs that are not cooked enough can still contain dangerous bacteria or parasites. Leaving food out at room temperature can give bacteria such as salmonella time to grow and produce toxins in the food. For these reasons, it is important to wash all used cooking tools. Chapter 27 Standardized Test Preparation

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following statements can you infer from this passage? A Treatment plants help keep drinking water safe. B Treatment plants never become flooded. C Eliminating treatment plants would help keep water safe. D New treatment plants are better than old ones. Chapter 27 Standardized Test Preparation

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Which of the following statements can you infer from this passage? A Treatment plants help keep drinking water safe. B Treatment plants never become flooded. C Eliminating treatment plants would help keep water safe. D New treatment plants are better than old ones. Chapter 27 Standardized Test Preparation

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Which of the following statements can you infer from the passage? F Bacteria that live in food produce more toxins than molds produce. G Cooking food thoroughly kills bacteria living in the food. H Some bacteria are helpful to humans. I Illnesses caused by bacteria living in food are seldom serious. Chapter 27 Standardized Test Preparation

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 2. Which of the following statements can you infer from the passage? F Bacteria that live in food produce more toxins than molds produce. G Cooking food thoroughly kills bacteria living in the food. H Some bacteria are helpful to humans. I Illnesses caused by bacteria living in food are seldom serious.

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. According to this passage, what do pathogens cause? A disease B flooding C water-line breaks D water supplies Chapter 27 Standardized Test Preparation

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. According to this passage, what do pathogens cause? A disease B flooding C water-line breaks D water supplies Chapter 27 Standardized Test Preparation

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Interpreting Graphics The graph below shows the reported number of people living with HIV/AIDS. Use the graph to answer the questions that follow. Chapter 27 Standardized Test Preparation

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. When did the number of people living with HIV/AIDS reach 5 million? A 1985 B 1986 C 1987 D 1988 Chapter 27 Standardized Test Preparation

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 1. When did the number of people living with HIV/AIDS reach 5 million? A 1985 B 1986 C 1987 D 1988

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. When did the number of people living with HIV/AIDS reach 30 million? F 1996 G 1997 H 1998 I 1999 Chapter 27 Standardized Test Preparation

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 2. When did the number of people living with HIV/AIDS reach 30 million? F 1996 G 1997 H 1998 I 1999

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. When was the rate of increase of people with HIV/AIDS the greatest? A from 1980 to 1982 B from 1984 to 1986 C from 1988 to 1990 D from 1998 to 2000 Chapter 27 Standardized Test Preparation

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 3. When was the rate of increase of people with HIV/AIDS the greatest? A from 1980 to 1982 B from 1984 to 1986 C from 1988 to 1990 D from 1998 to 2000

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 4. What percentage of the people who are infected with HIV do not yet have AIDS? F 10% G 24% H 75% I There is not enough information to determine the answer. Chapter 27 Standardized Test Preparation

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 4. What percentage of the people who are infected with HIV do not yet have AIDS? F 10% G 24% H 75% I There is not enough information to determine the answer.

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 5. If the virus continued to spread as the graph indicates, in the year 2002, about how many people would be infected with HIV? A 30 million B 35 million C 39 million D 60 million Chapter 27 Standardized Test Preparation

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 5. If the virus continued to spread as the graph indicates, in the year 2002, about how many people would be infected with HIV? A 30 million B 35 million C 39 million D 60 million

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 6. Which part of the graph indicates the rate of infection? F x-axis G y-axis H slope of the line being graphed I number of years in the sample Chapter 27 Standardized Test Preparation

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 6. Which part of the graph indicates the rate of infection? F x-axis G y-axis H slope of the line being graphed I number of years in the sample

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Math Read each question, and choose the best answer. Chapter 27 Standardized Test Preparation

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. Suppose you have 50,000 flu viruses on your fingers and you rub your eyes. Only 20,000 viruses enter your eyes, 10,000 dissolve in chemicals, and 10,000 are washed down into your nose. Of those, you sneeze out 2,000. How many viruses are left to wash down the back of your throat and possibly start an infection? A 50,000 B 10,000 C 8,000 D 5,000 Chapter 27 Standardized Test Preparation

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 1. Suppose you have 50,000 flu viruses on your fingers and you rub your eyes. Only 20,000 viruses enter your eyes, 10,000 dissolve in chemicals, and 10,000 are washed down into your nose. Of those, you sneeze out 2,000. How many viruses are left to wash down the back of your throat and possibly start an infection? A 50,000 B 10,000 C 8,000 D 5,000

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. In which of the following lists are the numbers in order from smallest to greatest? F 0.027, 0.072, 0.270, 0.720 G 0.270, 0.072, 0.720, 0.270 H 0.072, 0.027, 0.270, 0.720 I 0.720, 0.270, 0.072, 0.027 Chapter 27 Standardized Test Preparation

63. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation 2. In which of the following lists are the numbers in order from smallest to greatest? F 0.027, 0.072, 0.270, 0.720 G 0.270, 0.072, 0.720, 0.270 H 0.072, 0.027, 0.270, 0.720 I 0.720, 0.270, 0.072, 0.027

64. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27

65. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Your Body’s Defenses Chapter 27

66. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 27 Standardized Test Preparation