What is meant by 'system' in a biological context?

In a biological context, 'system' refers to a group of organs that collaborate to perform specific functions necessary for maintaining life and health. For instance, the circulatory system is made up of various organs, including the heart and blood vessels, which work together to circulate blood throughout the body. This interconnectedness is key; individual organs do not function in isolation but are part of a larger network that coordinates activities to ensure overall functionality and efficiency. This collective interaction allows organisms to perform complex processes, such as digestion, respiration, and thermoregulation, that sustain life.

Other options focus on more isolated definitions, such as a single organ or a collection of similar cells, and do not capture the holistic nature of how multiple organs interact. Additionally, the idea of all bodily functions occurring simultaneously encompasses too broad a range of activities without emphasizing the specific collaborative aspect central to the definition of a biological system.