An exploration of the biology of infectious diseases through the lens of the scientific method and core principles of life science. Students investigate microbial pathogens and their interactions with hosts through observation, hypothesis testing, experimentation, and data analysis. Concepts from microbiology, cell biology, human biology, and immunology are applied to explain how infections emerge, develop, adapt, and spread. Case studies such as HIV/AIDS and COVID-19 illustrate how genetic variation, antimicrobial resistance, climate change, and globalization drive the evolution and reemergence of infectious diseases. The course cultivates scientific literacy, evidence-based reasoning, and an understanding of the power and limitations of science in addressing global health challenges.