What do multiple organ systems working together form?

Multiple organ systems working together form an organism. This is because an organism represents a complete, functioning individual made up of various organ systems that coordinate and collaborate to maintain homeostasis and support life. Each organ system, such as the circulatory, respiratory, or digestive system, has specific functions, but they all rely on each other to operate efficiently and sustain the organism as a whole. In contrast, a cell is the basic unit of life, a tissue is a group of similar cells working together, and a system is generally a broader term that can apply to any organized group of elements working together, but it does not specify the level of biological organization that an organism encompasses.