This document provides an overview of viruses, their structure, replication cycles, and classification. It discusses that viruses are parasites that can only reproduce inside host cells. Viruses come in a variety of sizes and shapes, with the smallest being prions that are just proteins. Viruses can infect both eukaryotic and prokaryotic hosts. The document outlines the lytic and lysogenic replication cycles of viruses and bacteriophages, and provides examples like phage T4 and lambda. It also includes a table classifying different types of animal viruses based on their genome and presence of an envelope.

5. 3 Types of viruses or phages

7. 5 Lytic cycle of phage T4

8. 5 Lytic cycle of phage T4

10. 6 Lysogenic cycle of phage lambda λ

11. 6 Lysogenic cycle of phage lambda λ

13. Table 19.1 Classes of animal viruses Examples Envelop Class HIV, HLTV Yes ssRNA, retrovirus Filovirus, Rhabdovirus, Orthomyxovirus (Flu) Yes - ssRNA Picorna, Corona, Flavi, Toga +/- + ssRNA Reo No dsRNA Parvo No ssDNA Adeno, Papova, Herpes, Pox +/- dsDNA

14. Influenza in 1918