Which term refers to a set of interacting parts forming a complex whole, such as in an organism or ecosystem?

• A. Producer
• B. System
• C. Ecosystem
• D. Community

Answer: (B)

A system is a set of interacting parts that form a complex, unified whole. In biology this shows up both in organisms and in ecosystems. An organism is composed of interdependent subsystems—like the circulatory, respiratory, and nervous systems—that must work together to keep the whole organism functioning. An ecosystem can also be viewed as a system, where producers, consumers, decomposers, and the physical environment interact to transfer energy and recycle nutrients. The idea here is the interconnections and the emergent properties that appear only when parts operate together as a whole, not just by themselves. The other terms point to specific roles or levels—producers are energy-making organisms, a community is the group of populations in an area, and an ecosystem is a particular kind of system that includes both living and nonliving factors. So, the best fit for a set of interacting parts forming a complex whole is the concept of a system.