This course is designed to provide graduate and advanced undergraduate students with the basic understanding of what viruses are, their structures and replication strategies, including specific examples of disease-associated viruses. The basic molecular and cellular biology of viral replication will be discussed, with an emphasis on how distinctive viruses have evolved different strategies to accomplish similar biological functions. Further emphasis is placed on host-virus interactions leading to disease processes and cellular alterations in mammalian systems. Viruses are considered as miniature model systems to unify biology at the molecular level. Throughout the course, students will read and analyze primary scientific literature, as well as examples from lay media. Students will practice interpreting virological data and designing experiments to test hypotheses about viral function.