Name: _______________________ Period: _______

Chapter 25 Viruses

Sec 25-1 Structure of Viruses

1. Are viruses living or nonliving?

2. How can viruses be useful?

3. Explain how viruses were discovered and by whom.

4. Compare the size of viruses, bacteria, and eukaryotic cells.

5. What must be true for viruses to be able to replicate?

6. Name the two main parts of all viruses.

7. Discuss the hereditary material of viruses.

8. Compare & contrast capsids and envelopes of viruses.

9. Where are glycoproteins found & what is there purpose?

10. What characteristics are used to group viruses?

11. How are these viruses grouped --- retrovirus, adenovirus, and herpes virus?

12. Compare helical & icosahedral viral shapes & diseases.

13. Explain how RNA viruses replicate.

14. Do viruses contain enzymes? Explain.

15. Compare viroids & prions.

Sec 25-2 Viral Replication

16. Why are viruses considered to be obligate intracellular parasites?

17. What is the best known bacteriophage, and what bacteria does it attack?

18. Name the steps of the lytic cycle.

19. What are temperate phages and how do they affect a cell?

20. Name the steps of the lysogenic cycle.

21. How does a prophage form?

22. Name a sexually transmitted virus that uses the lysogenic cycle to attack host cells.

23. Why is the influenza virus so hard to combat?

Sec 25-3 Viruses & Human Disease

24. Name some of the most common viral disease that attack humans.

25. What two methods are used to control viral diseases?

26. What is the CDC and what is its job?

27. What eradication program did the World Health Organization undertake in 1967, and what were the results?

28. How does AZT work?

29. What drugs prevent viruses from making capsids?

30. Why is rain forest clearing dangerous to humans?

31. Some lysogenic viruses can trigger certain types of _________________.