Disease Unit Review Answers

1. Disease Unit ReviewAnswers

2. Section 19.1: Bacteria

3. 1. Draw or name the major parts of a bacteria cell. • - Cell membrane • - Cell wall (2 or 3) • - DNA or RNA (plasmid) • - Cytoplasm

4. 2. What two kingdoms are prokaryotes split into, and how do those two kingdoms differ? • Archaebacteria and Eubacteria • Differences: archaebacteria live in extreme environments • Eubacteria have peptidoglycan in their cell walls • DNA in archaebacteria is more like eukaryotic DNA

5. 3. Describe the four ways that prokaryotes are classified: • Shape/Arrangement • Movement (can move using flagella, or can’t move at all) • Gram Stain (Cell Wall structure) • Energy

6. 4. Draw and name the three different shapes and three different arrangements of bacteria • Shape (cocci [round], bacilli [rod shaped], spirilli [spiral]) • Arrangement: Can also be in staphylo (cluster) or strepto (long chain) arrangement or diplo (two)

7. 5. What are the differences between gram positive and gram negative bacteria in structure, color, and susceptibility to antibiotics? • Gram Stain- Gram Positive bacteria have two cell walls, and turn purple, antibiotics can be used against Gram Negative bacteria have three cell walls, and turn pink, cannot use antibiotics

8. 6. Describe two general ways that bacteria get energy from the environment • a. autotrophs: Make their own food using resources in the environment. • b. photoautotrophs: Make their own food using light energy, similar to photosynthesis.   • c. chemoautotrophs: Make their own food using chemicals in the environment. • d. heterotrophs: Rely on matter of other organisms for energy.

9. Section 19.2: Viruses

10. 7. Draw or list the main parts of a virus. • - protein coat (capsid) • - DNA or RNA (retroviruses have both)

11. 8. List three reasons why viruses are not considered to be living things: • a. they are parasites, needing a host to get energy • b. they have no control over their movement • c. they can’t reproduce on their own • d. no nucleus, cytoplasm, organelles, or cell membrane

12. 9. What is the difference between temperate and virulent viruses? • Temperate viruses do not make you very sick, and do not act quickly. They often stay in the lysogenic cycle. • Virulent viruses act very quickly, making you sick and entering the lytic cycle right away.

13. 10. What cell part is used to classify viruses? • Genetic material- do they have DNA or RNA

14. 11. Define viroid and prion, and explain what they do. • Viroid: genetic material on the run! DNA or RNA without a protein coat that hijacks cell enzymes to reproduce itself. • Prion: protein on the run! Proteins that use ribosomes in cells to reproduce themselves, making large protein plaques- mad cow disease is the accumulation of protein plaques in the brain.

15. 12. Draw or describe the lytic and lysogenic cycles of viral reproduction. How does the method of viral reproduction relate to a virus’ virulence? • Lyse- to burst open or shred the host cell • Lytic cycle: Virus injects its DNA or RNA into host; the virus reproduces itself using the cell’s organelles; within 1-2 days, the new viruses burst out of the cell and look for new cells to infect. • Lysogenic Cycle: Virus injects its DNA into host; DNA becomes part of host’s DNA; Viral DNA reproduces every time cell divides. • Virulent viruses tend to use the lytic cycle right away, making the host immediately ill. Lysogenic viruses can stay dormant, causing less severe, if any, illness.

16. Section 19.3: Diseases Caused by Bacteria and Viruses; Section 40.1: Infectious Disease

17. 13. Describe three ways that bacteria can be beneficial to us • Food, digestion, cleaning up toxic chemical areas

18. 14. Describe the four ways that bacterial disease is transmitted a. indirect transmission- touching a contaminated surface b. airborne transmission- droplets in the air c. direct transmission- person to person contact d. vector transmission (mosquito, tick)

19. 15. Explain two ways that bacteria cause disease. • a. Releasing toxins (botulism, strep throat) • b. Feeding off host tissues (flesh eating bacteria, tuberculosis)

20. 16. List three ways to prevent bacterial and viral diseases. • Sterilization through heat • Cleaning- antiseptics/disinfectants • Vaccines

21. 17. What are vaccines, and how are they used to treat viral and bacterial disease? • Vaccines are weakened or dead versions of a bacteria or virus. When we are injected with them, our immune system creates and stores antibodies to fight the disease when we get it for real.

22. 18. What are antibiotics, and how do they treat bacterial infections? • Antibiotics are toxins produced by bacteria to kill other bacteria in a competition for space on a host. They kill each other by disrupting cell walls. We have engineered bacteria to produce these antibiotics in large amounts, and to fight the bacteria we want them to. When you have a bacterial infection, you swallow or are injected with antibiotics to kill the infection inside of you.

23. 19. Explain how bacteria become resistant to antibiotics. • When not all the antibiotic is taken, bacteria become resistant by mutating, they pass on this resistance to their offspring as they reproduce.

24. 20. Why can’t antibiotics be used on viruses? • Antibiotics disrupt the cell wall of bacteria; since viruses don’t have cell walls, antibiotics don’t work.

25. 21. What treatment is available for viral diseases? • No treatment, some anti-virals, however there is prevention through vaccines (small doses of weakened versions of the virus).

26. 22. For the following diseases, list what organism/parasite them and how they are prevented/treated: • a. Influenza – Virus; vaccine to prevent, anti-viral medications to treat • b. Staph infection- Bacteria; vaccine to prevent, antibiotics to treat • c. E. coli food poisoning- Bacteria; vaccine to prevent, antibiotics to treat • d. Mad cow disease- Prion; no prevention or treatment • e. Malaria- Protist; does not respond to vaccines, antibiotics, or anti- virals • f. Common cold- Virus; vaccine to prevent, anti-viral to treat • g. HPV/Genital Warts- Virus; vaccine to prevent, anti-viral to treat • f. Syphilis- Bacteria; vaccine to prevent, antibiotic to treat

27. Ch. 40.2 Immune System

28. 23. List the five major causes of disease: • a. Bacteria • b. Protists • c. Worms • d. Fungi • e. viruses

29. 24. Describe four parts of your body’s first line of defense: • a. skin: provides a protective barrier against pathogens • b. mucus: traps pathogens and other foreign objects in nose, throat, and eyes. Cilia (tiny hairs) push the pathogens forward to be expelled from the body. • c. Digestive fluids: stomach is very acidic, killing pathogens trying to live there. • d. Enzymes in body fluids: lysozyme in blood and lymph fluid kills pathogens trying to live there.

30. 25. Describe how the inflammatory response, your body’s second line of defense, works. • When the first line of defense is broken, the inflammatory response occurs. Blood carries white blood cells (macrophages and phagocytes) to the scene to engulf pathogens. Your body raises its temperature (fever) to kill the pathogen that can’t live above 98.6 degrees. The area of infection gets red, swollen, and painful because of the blood flow and death of white blood cells who are battling the bacteria.

31. 26. What triggers cell-mediated versus humoral immunity? • Cell Mediated immunity is triggered by cells infected by viruses, or cells that have become cancerous. Humoral immunity is triggered by antigens in the blood stream and other bodily fluids.

32. 27. Describe the process of humoral immunity, including the action of Memory B Cells, Plasma Cells, and Antibodies. • B Cells bind to antigen, and become either Memory B cells or Plasma Cells. Memory B Cells are stored in lymph nodes, while Plasma Cells go into battle. Plasma Cells create antibodies that attack and destroy antigens. If you are infected with the same antigen again, the Memory B Cells divide to become Plasma Cells, who immediately have the antibodies to kill the antigen.

33. 28. Describe the process of cell-mediated immunity, including the actions of Killer T, Suppressor T, Memory T, and Helper T Cells. • The Helper T cells activates Killer T cells, who find and destroy infected cells by breaking through their cell membranes. Helper T cells also create Memory T cells to react faster to the same infection next time. Finally, Suppressor T cells turn off Killer T cells so they stop killing.

34. 29. Circle the following immune functions that are non-specific: First line of defense, inflammatory response, cell-mediated immunity, humoral immunity, interferons • Non Specific = first line of defense, inflammatory response, interferons • Specific = cell mediated, humoral immunity

35. 30. What is the difference between active immunity and passive immunity? • Active immunity: body produces its own antibodies in defense of a pathogen • Passive Immunity: antibodies are given to you, body does not make them on its own