The Biology of Sex and Death teaches biology through the lens of the formation and collapse of biological systems, organized around questions pertaining to life, sex, and death. The textbook was written by course instructors to align with specific conceptual knowledge and skills-oriented learning objectives. Sex and death are two constants of living organisms and are a consequence of how organisms interact with each other and the environment. Students explore questions such as why sex exists, how sexual reproduction differs between organisms, and what are the costs and benefits of sex. The course also covers modes of cancer and infectious disease, how genetic modification is used in agriculture, and how climate change and land use decisions by humans cause extinction, the death of entire species. Students will be able to demonstrate the ability to obtain, analyze, interpret, and criticize qualitative observations and quantitative measurements to explain natural phenomena and to test hypotheses.