4. Bacteriophages They are viruses that infect bacteria i.e. bacterial viruses (bacteria eater).

5. Main items 3-Replication 1-Discovery 2-General characteristics 4-Importance

6. Main items 1-Discovery

7. Discovery Twort (1915) D“herelle (1917)

8. Lytic agent may be a virus Bacteria + solid agar Thermal treatment

9. Bacillus dysentrae + solid agar Phenomenon due to bacteriophage

10. Main items 1-Discovery 2-General characteristics

11. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size 8.Cultivation.

12. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size 8.Cultivation.

14. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size. 8.Cultivation.

15. : Symmetry : 1. Helical 2. Cubic

24. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size. 8.Cultivation.

25. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size. 8.Cultivation.

26. A B C D E F

29. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size. 8.Cultivation.

30. Replication 1. Virulent (Lytic) 2. Avirulent (lysogenic or temperate)

32. General characteristics 1.Widely distributed. 2.Structure. 3.Symmetry. 4.Nucleic acid. 5.Morphology. 6.Replication. 7.Size. 8.Cultivation.

33. Main items 3-Replication 1-Discovery 2-General characteristics

34. Lytic cycle Replication Penetration Adsorption Assembly Releasing

40. Summary of virulent cycle

41. Lysogeny cycle Integration Penetration Adsorption Bacterial duplication Spontaneous induction Replication Assembly Releasing

49. Mutation of temperate phage to virulent phage Resistant to repressor molecule. Loss repressor molecule production.

52. Main items 3-Replication 1-Discovery 2-General characteristics 4-Importance

53. Importance Viral research Genetic engineering Viral pathogenicity Medical diagnosis (phage typing by virulent) Medical aspects of lysogeny (lysogenic conversion)